SlideShare a Scribd company logo

2 pumps part 2 including centrifugal pumps rev 4

•Download as PPTX, PDF•
•
A
alyaly_mw

2 pumps part 2 including centrifugal pumps rev 4

Engineering
1 of 81
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / / Rev 2 ACADBasics@gpworldwide.com ACAD BASIC CURRICULUM MECHANICAL SCIENCE Chapter 2 Part 2 – Centrifugal Pumps PISTON ROD VALVE VALVE VALVE PISTON PACKING PISTON DISCHARGE MANIFOLD SUCTION MANIFOLD PISTON-ROD PACKING MOTION SUCTION PIPE DISCHARGE PIPE PISTON ROD VALVE VALVE VALVE VALVE PISTON PACKING PISTON DISCHARGE MANIFOLD SUCTION MANIFOLD PISTON-ROD PACKING MOTION SUCTION PIPE DISCHARGE PIPE VALVE IMPELLER WEARING RINGINLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING
© 2003 General Physics Corporation PUMP CLASSIFICATIONS PUMPS Kinetic (Dynamic) Positive Displacement Part 1 Part 2
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 2 / Rev 02 OBJECTIVES 12. STATE the purpose of the following centrifugal pump components: a. Casing e. Bearings b. Gaskets f. Seal rings c. Impeller g. Volute d. Shaft h. Shaft seals 13. DESCRIBE the operation of the following types of centrifugal pumps: a. Volute and diffuser pumps b. Radial-flow, axial-flow and mixed-flow pumps 14. DESCRIBE the operation of centrifugal pumps, including requirements for the following: a. NPSH b. Starting a centrifugal pump c. Operation with a centrifugal pump dead headed d. Minimum flow e. Prevention of runout Part 2 has 12 objectives.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 3 / Rev 02 OBJECTIVES 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. 16. EXPLAIN the three centrifugal pump laws. 17. DETERMINE the effects of changes for a centrifugal pump in flow, pump speed, or system characteristic curve on the system operating point. 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention. 19. DRAW and LABEL characteristic curves for centrifugal pumps.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 4 / Rev 02 OBJECTIVES 20. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: a. One pump in slow speed b. One pump in fast speed c. Two pumps in parallel d. Two pumps in series 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. 22. DESCRIBE the operation of jet pumps. 23. DESCRIBE what items are included in post maintenance testing. 24. IDENTIFY and DESCRIBE auxiliary support equipment associated with pumps. [Not included in Mechanical Technology I]
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 5 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Most common pump used in industry.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 6 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 • Centrifugal force is the outward force. • Centrifugal pumps turn kinetic energy into flow energy (pressure). • Wide range of pressures and flow rates. • Basic process:  Shaft (driven by motor)  Fluid enters the suction eye  Impeller pushes the water and increases its speed  Water moves outward moving very fast  The volute widens and KE is turned into pressure.
© 2003 General Physics Corporation CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Objective 12. STATE the purpose of the following centrifugal pump components: a. Casing b. Gaskets c. Impeller d. Shaft e. Bearings f. Seal rings g. Volute h. Shaft seals
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 8 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 8 major components of a centrifugal pump: • Casing • Gaskets • Impeller • Shaft • Bearings • Seal rings • Volute • Shaft seals Objective 12
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 9 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The pump casing houses the majority of the major pump components. • The inlet (suction) and outlet (discharge) connections are integral to the pump casing. Objective 12a
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 10 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The faces of the casing are machined to fit together smoothly, but the finest machining still has some leakage. Objective 12a
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 11 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The faces of the casing are machined to fit together smoothly, but the finest machining still has some leakage. • Gaskets are used to reduce leakage • Gaskets are semi-soft flexible materials used to seal mating surfaces or flanges. Objective 12ab
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 12 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Impeller • The impeller is the rotating component of the pump that converts the mechanical energy of the prime mover (the pump motor) into kinetic energy (velocity) in the fluid. • The impeller is mounted on the pump Shaft. Objective 12c
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 13 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Shaft • The shaft connects the prime mover to the impeller. • This may be done either directly or through a flexible coupling. • The function of the pump shaft is to transmit the torque from the prime mover to the impeller. Objective 12d
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 14 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Bearings • The shaft is supported by bearings. • Bearings provide two types of support, radial support for side to side motion and axial support for movement along the axis. Objective 12e
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 15 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Bearings • The radial support is provided by antifriction journal bearings. • The bearings that provide the axial support are called thrust bearings. Objective 12e
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 16 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Seal rings • The casing rings and wearing rings provide the seal needed between the impeller and the casing. • This seal prevents high-pressure discharge water from leaking back to the low pressure suction side of the impeller. Objective 12f
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 17 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Seal rings • The wearing rings also prevent excessive wearing (erosion) of the pump casing. • The casing ring fits into the casing and the wearing ring fits onto the impeller and rotates with it. Objective 12f
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 18 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Volute • The volute is a gradually expanding spiral that is integral to the casing. • It reduces fluid velocity and increases fluid pressure. Objective 12g
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 19 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Shaft seals • In almost all centrifugal pumps, the rotating shaft that drives the impeller penetrates the pressure boundary of the pump casing. Objective 12h
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 20 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 8 major components of a centrifugal pump: Shaft seals • There are many different methods of sealing the shaft penetration of the pump casing. Objective 12h
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 21 / Rev 02 OPEN IMPELLER Fig 2-30 • Vanes always “sling” the water out. • They do not “dig in”. • If installed backwards or if the prime mover rotates in reverse, the pump will operate at a significantly reduced capacity. • The open impeller consists only of blades attached to a hub. • Open impellers are good for pumping liquids containing solids because they do not clog. PUMP ROTATION
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 22 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 23 / Rev 02 SEMI-CLOSED IMPELLER PUMP ROTATION Fig 2-31 • Semi-enclosed impellers are more efficient than the open impeller. • The design also enables the impeller to move water against greater backpressure.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 24 / Rev 02 CLOSED IMPELLER Fig 2-32 • Although it is more expensive, the closed impeller is more efficient than the open impeller. • It also offers the advantage of reduced wear due to less erosion of the impeller vanes. • This pump performance remains consistent throughout pump life.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 25 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 26 / Rev 02 SINGLE-SUCTION IMPELLER C. RADIAL VIEW OF PUMP B. CROSS-SECTION VIEW OF IMPELLER OUT SHAFT IN IN OUT A. ANGLE VIEW OF IMPELLER IN IN OUT OUT OUT PUMP INTAKE WEARING RING IMPELLER CASING STUFFING BOX OR PACKING GLAND Fig 2-34 Thrust Force
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 27 / Rev 02 DOUBLE-SUCTION IMPELLER (A) ANGLE VIEW OF DOUBLE- SUCTION IMPELLER IN IN IN IN OUT (B) CROSS SECTION OF THE IMPELLER IN IN IN IN OUT OUT (C) CROSS SECTION OF THE PUMP IMPELLERWEARING RING STUFFING BOX SHAFT CASING Fig 2-35 Thrust force is eliminated.
© 2003 General Physics Corporation CENTRIFUGAL PUMP Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction. • Vertical or horizontal
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 29 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction • Vertical or horizontal • Single-stage, double-stage, or multi- stage
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 30 / Rev 02 FLOW THROUGH A MULTI-STAGE PUMP SUCTION IMPELLERS DISCHARGE SHAFT BALANCING LINE HIGH PRESSURE LOW PRESSURE AXIAL THRUST BALANCING DRUM SHAFT SUCTION IMPELLERS DISCHARGE SHAFT BALANCING LINE HIGH PRESSURE LOW PRESSURE AXIAL THRUST BALANCING DRUM SHAFT Fig 2-36 • Each impeller is considered to be a "pressure stage".
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 31 / Rev 02 MULTI-STAGE SINGLE AND DOUBLE SUCTION IMPELLER FLOW PATH DOUBLE ADMISSION SINGLE ADMISSION ADMISSION DISCHARGE DISCHARGE ADMISSION Fig 2-37
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 32 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction. • Vertical or horizontal • Single-stage, double-stage, or multi- stage • Volute or diffuser
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 33 / Rev 02 VOLUTE AND DIFFUSER PUMPS VOLUTE DIFFUSER ROTATING IMPELLER STATIONARY DIFFUSER VANES Objective 13a. DESCRIBE the operation of the following types of centrifugal pumps: Volute and diffuser pumps
© 2003 General Physics Corporation DIFFUSER CENTRIFUGAL PUMPS • In diffuser pumps, the volute is enhanced with a diffuser and a series of stationary vanes arranged around the impeller. 1) The purpose of the diffuser is to increase the efficiency of the centrifugal pump by straightening the flow in the volute. a) This reduces turbulence and allows a more gradual conversion of velocity head to pressure head. 2) Since the vanes are farther apart at their outermost points than at the edge of the impeller, they create a series of widening chambers that convert kinetic energy into pressure in the same way that a volute does. 3) The diffuser vane helps balance the radial thrust loads on the impeller, shaft, and journal bearings for varying flow conditions. Objective 13a
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 35 / Rev 02 PACKING SEALS Fig 2-42 PACKING GLAND STUFFING BOX LIQUID SEAL SUPPLY SHAFT LANTERN RING PACKING There must be a seal where the shaft penetrates the casing to prevent the pumped fluid from leaking out around the rotating shaft. • This is accomplished with a shaft seal. • A shaft seal can be a stuffing box or a mechanical seal.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 38 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 Objective 13b. DESCRIBE the operation of the following types of centrifugal pumps: Radial-flow, axial-flow and mixed-flow pumps
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 39 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 • By radically changing the direction of flow and directing the fluid through a volute, radial-flow pumps are able to create a high discharge pressure.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 40 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 • In contrast, axial-flow pump can move tremendous volumes of fluid • but at relatively low discharg pressures.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 41 / Rev 02 MIXED-FLOW PUMP SUCTION SHAFT VOLUTE DISCHARGE IMPELLER VANE SUCTION SHAFT VOLUTE DISCHARGE IMPELLER VANE Fig 2-41 • Mixed-flow pumps combine, to some degree, the functions of radial-flow pumps and axial flow pumps.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 42 / Rev 02 Centrifugal Pump Operation Objective 14b. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Starting a centrifugal pump RECIRC LINE PUMP CHECK VALVE DISCHARGE VALVE SUCTION VALVE VENT VALVE DRAIN VALVE
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 43 / Rev 02 Centrifugal Pump Operation Fig 2-56 Objective 14b. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Starting a centrifugal pump • A centrifugal pump is not self priming and requires adequate net positive suction head (NPSH) to prevent cavitation. • There are two reasons for closing the discharge valve: First, it minimizes the chances of pump runout. [Objective 14e and 18] Second, it prevents backflow through the pump that can result in abnormally high starting currents, which could damage the motor windings. Fig 2-57
© 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • Many centrifugal pumps are designed to operate continuously for months or even years. • Closing the pump discharge valve while the pump is still operating stops flow through the pump and the pump will no longer be adequately cooled. • Pump damage can also result from pumping a liquid whose temperature is close to saturated conditions. • Overheating will occur if a pump is operated against a closed valve (dead headed) for more than a few minutes. Objective 14c. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Operation with a centrifugal pump dead headed.
© 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • This is called operating at shutoff head. • Shutoff head is generally defined as the maximum value of head that a pump can produce. • Operating a centrifugal pump with the discharge valve closed is also called dead heading the pump. • Because the fluid in the pump has no where to go the spinning impeller heats the fluid. • This has two disastrous results. Objective 14c. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Operation with a centrifugal pump dead headed.
© 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • This has two disastrous results. 1) Heat from the heated fluid is transferred to the internal pump components. a) This can cause damage to bearings and components with close tolerances. b) The casing and wearing rings may expand from the heat and come in contact with one another. 2) Secondly, the heated fluid may reduce the net positive suction head available by raising the temperature of the fluid to a saturated temperature. a) As the fluid reaches saturated temperature it also reaches saturation pressure. b) This can result in cavitation of the pump and severe and rapid damage. Objective 14a. NPSH.
© 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING In many applications, a bypass or minimum flow line prevents the pump from operating at shutoff head. • With these modifications, an amount of flow necessary to cool the pump can be maintained. • The smallest amount of flow that prevents overheating is called the pump minimum flow requirement. Objective 14d. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Minimum flow. Fig 2-57
© 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING In many applications, a bypass or minimum flow line prevents the pump from operating at shutoff head. Objective 14d. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Minimum flow. RECIRC LINE PUMP CHECK VALVE DISCHARGE VALVE SUCTION VALVE VENT VALVE DRAIN VALVE Fig 2-57
© 2003 General Physics Corporation CENTRIFUGAL PUMP LAW EQUATIONS Objective 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. Objective 16. EXPLAIN the three centrifugal pump laws. These laws state that a. the volumetric flow rate or capacity is directly proportional to the pump speed, b. the discharge head (pressure) is directly proportional to the square of the pump speed, and c. the power required by the pump motor is directly proportional to the cube of the pump speed.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 50 / Rev 02 CENTRIFUGAL PUMP LAWS Where: = pump volumetric flow rate (m3/s, m3/min, m3/hr)  = proportional N = pump speed (rpm) Hp = pump discharge head (Pa) P = pump power (W) NV  Hp  N2 P  N3 V Eq 2-14 flow pump load power
© 2003 General Physics Corporation CENTRIFUGAL PUMP LAW EQUATIONS Where: = initial pump speed = proportional 2 1 2 1 V )N( )N( V   p22 1 2 2 p1 H )(N )(N H  23 1 3 2 1 P )N( )N( P  N1 N2 Objective 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. Objective 16. EXPLAIN the three centrifugal pump laws. flow pump load power
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 52 / Rev 02 EXAMPLE 2-17 A regulating water pump is operating at 1,000 rpm. Its capacity is 50.0 m3/hour at a discharge head of 70 kPa that requires a power of 50 kW. Determine the pump capacity, discharge head, and power requirements if the pump speed is increased to 2,000 rpm. Ex 2-17
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 53 / Rev 02 EXAMPLE 2-17 (continued) The pump speed is increased by a factor of two; therefore, the capacity is increased by a factor of two. Using the equation for capacity: Ex 2-17
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 54 / Rev 02 EXAMPLE 2-17 (continued) If the pump speed is increased by a factor of two, the discharge head is increased by a factor of two squared. Using the equation for discharge head: Ex 2-17 p22 1 2 2 p1 H )(N )(N H 
© 2003 General Physics Corporation EXAMPLE 2-17 (continued) If the pump speed is increased by a factor of two, the power requirement is increased by a factor of two cubed. Using the equation for power:
© 2003 General Physics Corporation CENTRIFUGAL PUMP CHARACTERISTICS Objective 17. DETERMINE the effects of changes for a centrifugal pump in flow, pump speed, or system characteristic curve on the system operating point. One of the most important characteristics of a pump is its capacity, or how much fluid it moves per unit time. • The capacity of a centrifugal pump decreases as the pressure at the pump discharge increases. • At a particular pressure, called the shutoff head, the pump moves no fluid at all. • A plot for a centrifugal pump that shows discharge head versus capacity for a given pump speed is often called the pump characteristic curve. Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention [Objective 14e].
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 57 / Rev 02 CENTRIFUGAL PUMP CHARACTERISTIC CURVE Fig 2-44 CAPACITY (m3/h  435) DISCHARGEHEAD(mx3.3) 0 0.25 0.5 0.75 1 1.25 1. 1.75 2.0 60 54 48 42 36 30 24 18 12 6 0 PUMP SHUTOFF HEAD PUMP RUNOUT Objective 19. DRAW and LABEL characteristic curves for centrifugal pumps.
© 2003 General Physics Corporation Effects at Shutoff Head Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention. At shutoff head (also called “dead-headed”) the pump is producing the maximum value of discharge head. However, a pump can only operate at shutoff head for only a few minutes. • The resulting friction increases pump and fluid temperature. • Overheating of the pump may occur at this point.
© 2003 General Physics Corporation Effects at Runout • Runout, an abnormally high flow rate from a centrifugal pump, can lead to mechanical stress on the pump and excessive motor current. • If the pump discharges directly to the atmosphere, the pump capacity is at its maximum. • Runout is the result of a loss of downstream pressure (piping not filled and vented, leak or pipe break). • The drop in pressure speeds up the pump and causes excessive motor current, which may result in damage to the windings. • The low backpressure can also result in cavitation and excessive flow. Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention.
© 2003 General Physics Corporation Prevention of Runout • To help prevent runout, ensure proper venting and filling of systems before pump startup. • High motor current trips protect pump motors from winding damage due to runout. • Limit the flow (“One method for ensuring that there is always adequate flow resistance at the pump discharge to prevent excessive flow through the pump is to place an orifice or a throttle valve immediately downstream of the pump discharge. Properly designed piping systems are very important to protect from runout.”) Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention [Objective 14e].
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 61 / Rev 02 EFFECT OF DOUBLING CENTRIFUGAL PUMP SPEED Fig 2-45 Objective 20. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: a. One pump in slow speed b. One pump in fast speed c. Two pumps in parallel d. Two pumps in series • Based on the pump laws previously discussed, if the pump speeds up, the entire characteristic curve moves outward, away from the origin. • The pump capacity increases by the same factor as the speed increases, and the pump discharge head increases as the square of the factor by which the speed increases.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 62 / Rev 02 EFFECT OF DOUBLING CENTRIFUGAL PUMP SPEED Fig 2-45 CAPACITY (m3/h x 435) DISCHARGEHEAD(mx3.3) 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 220 214 208 202 196 190 182 176 170 164 158 152 146 140 134 128 122 116 110 104 98 90 84 78 72 66 60 54 48 42 36 30 24 18 12 6 0 Objective 20a,b • If the pump operates at constant efficiency, the power required to operate the pump at a new speed increases as the cube of the factor by which the speed increases. • However, pump efficiency varies widely over an operating range and with speed as well.
© 2003 General Physics Corporation CENTRIFUGAL PUMP CHARACTERISTIC CURVES 0 25 75 125 CAPACITY (m3/h x 435) 40 50 30 20 0 10 DISCHARGEHEAD(mx3.3) 80 100 60 40 0 20 EFFICIENCY(%) PUMP CHARACTERISTIC EFFICIENCY CURVE SYSTEM OPERATING CURVE OPERATING POINT Fig 2-46
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 64 / Rev 02 CENTRIFUGAL PUMP CHARACTERISTIC CURVES 0 25 75 125 CAPACITY (m3/h x 435) 60 0 40 POWER(HP) 80 20 0 25 75 125 CAPACITY (m3/h x 435) 40 50 30 20 0 10 DISCHARGEHEAD(mx3.3) 80 100 60 40 0 20 EFFICIENCY(%) PUMP CHARACTERISTIC EFFICIENCY CURVE SYSTEM OPERATING CURVE OPERATING POINT Fig 2-46
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 65 / Rev 02 HEAD vs. FLOW FOR A CENTRIFUGAL PUMP PUMPHEAD(FEET) VOLUMETRIC FLOW RATE NEW OPERATING POINT VALVE PARTIALLY SHUT VALVE OPEN INITIAL OPERATING POINT SYSTEM OPERATING CURVES Fig 2-47
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 66 / Rev 02 CENTRIFUGAL PUMPS IN PARALLEL PUMP CHECK VALVE Fig 2-48 Objective 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. • This type of configuration is useful when the demand for volume fluctuates. • One pump can be operated when the demand is low, and the second pump can be started and used when the fluid flow requirement increases beyond the capacity of the first pump. • This arrangement also provides system component redundancy and backup.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 67 / Rev 02 PUMP CURVES FOR IDENTICAL CENTRIFUGAL PUMPS IN SINGLE AND PARALLEL OPERATION Fig 2-49 PUMPS A and B 4” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY ( m3/h x 435) 30 35 40 2 1 Objective 20c. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: Two pumps in parallel.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 68 / Rev 02 SINGLE CENTRIFUGAL PUMP OPERATION WITH SYSTEM VARIATION Fig 2-52 PUMPS A and B 4” pipe 5” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY (m3/h x 435) 30 35 40 1 2
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 69 / Rev 02 CENTRIFUGAL PUMPS IN PARALLEL WITH SYSTEM VARIATIONS Fig 2-53 PUMPS A and B 4” pipe 5” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY (m3/h x 435) 30 35 40 1 3 2 4
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 70 / Rev 02 CENTRIFUGAL PUMPS IN SERIES Fig 2-54 Objective 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. Objective 20d. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: Two pumps in series.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 71 / Rev 02 CENTRIFUGAL PUMPS IN SERIES CHARACTERISTIC CURVES Fig 2-55 48 36 24 0 6 0 5 10 15 20 25 TOTALHEAD(mx3.3) PUMP A plus B 72 60 12 30 CAPACITY (m3/h x 435) PUMP A or B SYSTEM OPERATING CURVE • For an efficient unit, capacities at best efficiencies for the individual pumps should be about the same.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 72 / Rev 02 OPEN SYSTEM CHARACTERISTIC CURVES FOR CENTRIFUGAL PUMPS Fig 2-56 PUMPHEAD(FEET) VOLUMETRIC FLOW RATE NEW OPERATING POINT VALVE PARTIALLY SHUT VALVE OPEN INITIAL OPERATING POINT PUMP CHARACTERISTIC CURVE Static Head SYSTEM OPERATING CURVES • While some aspects of Open System operation are similar to Closed System operation, other aspects are completely different. • Most notably, the pump laws DO NOT APPLY to open system situations in which the system inlet and discharge points are at different pressures or elevations.
© 2003 General Physics Corporation CENTRIFUGAL PUMP OPERATION • 1. Line up auxiliary items. • 2. Open the pump suction valve. • 3. Prime the pump. • 4. Shut the pump discharge valve, or verify • that it is shut. • 5. Start the pump motor. • 6. Slowly open the pump discharge valve. ABC / Mechanical Science / Chapter 2 / TP 2 - 73 / Rev 02
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 74 / Rev 02 EDUCTOR CONSTRUCTION CONDENSER GASES AND VAPORS TO BE COMPRESSED SUCTION CHAMBER STEAM STEAM NOZZLE CONVERGENT DIFFUSER NOZZLE DIFFUSER DIVERGENT DIFFUSER NOZZLE STRAIGHT THROAT Fig 2-58 Objective 22. DESCRIBE the operation of jet pumps.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 75 / Rev 02 EDUCTOR CONSTRUCTION Fig 2-58 • Jet pumps are static (static in this use means no moving parts) devices that convert high pressure driving flow developed by an external source into a high velocity jet flow at low pressure. • The fluid to be moved surrounds the high velocity jet. • The benefits of this pump are low maintenance, high reliability, and small size when compared with other pumps of the same capacity. • A disadvantage is the need for a high pressure supply to develop the required high head for the driving flow. Objective 22. DESCRIBE the operation of jet pumps.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 76 / Rev 02 MACH NUMBER EQUATION Where: Nm = Mach number V = velocity of mixture C = sonic velocity for the given material and conditions C V Nm  Eq 2-16
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 77 / Rev 02 MACH NUMBER EQUATION (cont’d) Nm < 1 subsonic Nm = 1 sonic Nm > 1 supersonic Eq 2-16
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 78 / Rev 02 STEAM JET AIR EJECTOR STEAM ONLY AIR ONLY STEAM & AIR MIXTURE MACH 1 VELOCITY SUPERSONIC VELOCITY SUBSONIC VELOCITY SONIC VELOCITY CONDENSER GAS & VAPORS TO BE COMPRESSED SUCTION CHAMBER STEAM STEAM NOZZLE DIVERGENT DIFFUSER NOZZLE STRAIGHT THROAT STEAM & AIR DISCHARGE DIFFUSER CONVERGENT DIFFUSER NOZZLE STEAM & AIR DISCHARGE PRESSURE CONDENSER VACUUM PRESSURE STEAM PRESSURE STEAM EJECTOR OPERATING STEAM PRESSURE Fig 2-59
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 79 / Rev 02 JET PUMP OPERATING PRINCIPLES Fig 2-60 PRESSURE SUCTION FLOW DRIVING FLOW (1/3) SUCTION OR DRIVEN FLOW (2/3) DRIVING FLOW DP DRIVING FLOW PRESSURE THROAT OR MIXING SECTION SUCTION FLOW DP PRESSURE DISTANCE DIFFUSER DRIVING NOZZLE
© 2003 General Physics Corporation POST MAINTENANCE TESTING Objective 23. DESCRIBE what items are included in post maintenance testing. Post-maintenance tests can include: • Leakage tests to verify the leakage past shaft seals are within the specification for that pump and its application. • Verification of pump responses to automatic initiation and trip signals. • Flow verification to ensure the pump is capable of delivering the required flow and pressure. • Hydrostatic testing to ensure all connections are capable of withstanding the normal operating conditions to which the pump will be exposed. • Vibration testing to ensure the pump shaft alignment and component installation has been performed correctly and to establish base line data for future testing of the pump.
© 2003 General Physics Corporation POST MAINTENANCE TESTING Objective 24. IDENTIFY and DESCRIBE auxiliary support equipment associated with pumps. Not covered in course material, so it will not be covered on the Final Examination.
© 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 82 / Rev 02 OBJ QUESTIONS & ANSWERS

Recommended

Fundamentals of mechanical seals
Fundamentals of mechanical sealsFundamentals of mechanical seals
Fundamentals of mechanical seals
Prem Baboo
 
Hydraulic Intensifier ( Pressure raising device )
Hydraulic Intensifier ( Pressure raising device ) Hydraulic Intensifier ( Pressure raising device )
Hydraulic Intensifier ( Pressure raising device )
Umar Saeed
 
Centrifugal pump sizing tutorial
Centrifugal pump sizing tutorialCentrifugal pump sizing tutorial
Centrifugal pump sizing tutorial
Telema Harry, Provisional Lic.(Eng.), PMP®, M.Sc
 
Testing of Safety Valves
Testing of Safety ValvesTesting of Safety Valves
Testing of Safety Valves
Carl Stevens
 
Hydraulic systems
Hydraulic systemsHydraulic systems
Hydraulic systems
Thulasikanth Vaddi
 
pumps
pumpspumps
pumps
Ehab Abowarda
 
Compressors
CompressorsCompressors
Compressors
Mohammad Azam Khan
 
Industrial Solenoid Valves, Bronze and Stainless Steel
Industrial Solenoid Valves, Bronze and Stainless SteelIndustrial Solenoid Valves, Bronze and Stainless Steel
Industrial Solenoid Valves, Bronze and Stainless Steel
Miller Energy, Inc.
 

Recommended

Fundamentals of mechanical seals
Fundamentals of mechanical sealsFundamentals of mechanical seals
Fundamentals of mechanical seals
Prem Baboo
 
Hydraulic Intensifier ( Pressure raising device )
Hydraulic Intensifier ( Pressure raising device ) Hydraulic Intensifier ( Pressure raising device )
Hydraulic Intensifier ( Pressure raising device )
Umar Saeed
 
Centrifugal pump sizing tutorial
Centrifugal pump sizing tutorialCentrifugal pump sizing tutorial
Centrifugal pump sizing tutorial
Telema Harry, Provisional Lic.(Eng.), PMP®, M.Sc
 
Testing of Safety Valves
Testing of Safety ValvesTesting of Safety Valves
Testing of Safety Valves
Carl Stevens
 
Hydraulic systems
Hydraulic systemsHydraulic systems
Hydraulic systems
Thulasikanth Vaddi
 
pumps
pumpspumps
pumps
Ehab Abowarda
 
Compressors
CompressorsCompressors
Compressors
Mohammad Azam Khan
 
Industrial Solenoid Valves, Bronze and Stainless Steel
Industrial Solenoid Valves, Bronze and Stainless SteelIndustrial Solenoid Valves, Bronze and Stainless Steel
Industrial Solenoid Valves, Bronze and Stainless Steel
Miller Energy, Inc.
 
Hydraulic beginner
Hydraulic beginnerHydraulic beginner
Hydraulic beginner
Aditya Kurniawan
 
Hydraulic Circuit Design and Analysis , dr.samir elshamy
Hydraulic Circuit Design and Analysis , dr.samir elshamyHydraulic Circuit Design and Analysis , dr.samir elshamy
Hydraulic Circuit Design and Analysis , dr.samir elshamy
Dr.Samir el-shamy
 
Different types of control valves
Different types of control valvesDifferent types of control valves
Different types of control valves
Prem Baboo
 
Hydraulic Valves and Hydraulic System Accessories
Hydraulic Valves and Hydraulic System AccessoriesHydraulic Valves and Hydraulic System Accessories
Hydraulic Valves and Hydraulic System Accessories
RAHUL THAKER
 
Hydraulic Maintenance and Troubleshooting
Hydraulic Maintenance and TroubleshootingHydraulic Maintenance and Troubleshooting
Hydraulic Maintenance and Troubleshooting
CMA/Flodyne/Hydradyne
 
Pumps
PumpsPumps
Pumps
Mahmudul Hasan
 
multi stage pump
multi stage pumpmulti stage pump
multi stage pump
jaimin kemkar
 
Difference Types of Control Valves Presentation.pdf
Difference Types of Control Valves Presentation.pdfDifference Types of Control Valves Presentation.pdf
Difference Types of Control Valves Presentation.pdf
Souraj Ranjan Patel
 
Mechanical Valve
Mechanical ValveMechanical Valve
Mechanical Valve
Nathan
 
Pump
PumpPump
Pump
Prasadroshan Mythin
 
Basics of pump
Basics of pump Basics of pump
Basics of pump
Hammad Akber
 
Introduction to Stress Analysis and Piping Vibration Analysis
Introduction to Stress Analysis and Piping Vibration AnalysisIntroduction to Stress Analysis and Piping Vibration Analysis
Introduction to Stress Analysis and Piping Vibration Analysis
André Fraga
 
Radial and axial thrust in centrifugal pump and Methods use to balance them
Radial and axial thrust in centrifugal pump and Methods use to balance themRadial and axial thrust in centrifugal pump and Methods use to balance them
Radial and axial thrust in centrifugal pump and Methods use to balance them
shankar shegade
 
Control valves
Control valvesControl valves
Control valves
SHIVAJI CHOUDHURY
 
PID control for process safety.pdf
PID control for process safety.pdfPID control for process safety.pdf
PID control for process safety.pdf
SMTauseef1
 
ARMACO STANDARD
ARMACO STANDARDARMACO STANDARD
ARMACO STANDARD
Irfan Ali
 
Pressure Relief Devices
Pressure Relief DevicesPressure Relief Devices
Pressure Relief Devices
ie-net ingenieursvereniging vzw
 
Overview of Pressure Relief Valve
Overview of Pressure Relief ValveOverview of Pressure Relief Valve
Overview of Pressure Relief Valve
Abhishek Nayak
 
Piston pumps
Piston pumpsPiston pumps
Piston pumps
jitendra mandal
 
Fundamentals of Centrifugal Compressor - Head (revised)
Fundamentals of Centrifugal Compressor - Head (revised)Fundamentals of Centrifugal Compressor - Head (revised)
Fundamentals of Centrifugal Compressor - Head (revised)
Sudhindra Tiwari
 
Design of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic couplingDesign of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic coupling
ijmech
 
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINEDESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
ijiert bestjournal
 

More Related Content

What's hot

What's hot (20)

Hydraulic beginner
Hydraulic beginnerHydraulic beginner
Hydraulic beginner
 
Hydraulic Circuit Design and Analysis , dr.samir elshamy
Hydraulic Circuit Design and Analysis , dr.samir elshamyHydraulic Circuit Design and Analysis , dr.samir elshamy
Hydraulic Circuit Design and Analysis , dr.samir elshamy
 
Different types of control valves
Different types of control valvesDifferent types of control valves
Different types of control valves
 
Hydraulic Valves and Hydraulic System Accessories
Hydraulic Valves and Hydraulic System AccessoriesHydraulic Valves and Hydraulic System Accessories
Hydraulic Valves and Hydraulic System Accessories
 
Hydraulic Maintenance and Troubleshooting
Hydraulic Maintenance and TroubleshootingHydraulic Maintenance and Troubleshooting
Hydraulic Maintenance and Troubleshooting
 
Pumps
PumpsPumps
Pumps
 
multi stage pump
multi stage pumpmulti stage pump
multi stage pump
 
Difference Types of Control Valves Presentation.pdf
Difference Types of Control Valves Presentation.pdfDifference Types of Control Valves Presentation.pdf
Difference Types of Control Valves Presentation.pdf
 
Mechanical Valve
Mechanical ValveMechanical Valve
Mechanical Valve
 
Pump
PumpPump
Pump
 
Basics of pump
Basics of pump Basics of pump
Basics of pump
 
Introduction to Stress Analysis and Piping Vibration Analysis
Introduction to Stress Analysis and Piping Vibration AnalysisIntroduction to Stress Analysis and Piping Vibration Analysis
Introduction to Stress Analysis and Piping Vibration Analysis
 
Radial and axial thrust in centrifugal pump and Methods use to balance them
Radial and axial thrust in centrifugal pump and Methods use to balance themRadial and axial thrust in centrifugal pump and Methods use to balance them
Radial and axial thrust in centrifugal pump and Methods use to balance them
 
Control valves
Control valvesControl valves
Control valves
 
PID control for process safety.pdf
PID control for process safety.pdfPID control for process safety.pdf
PID control for process safety.pdf
 
ARMACO STANDARD
ARMACO STANDARDARMACO STANDARD
ARMACO STANDARD
 
Pressure Relief Devices
Pressure Relief DevicesPressure Relief Devices
Pressure Relief Devices
 
Overview of Pressure Relief Valve
Overview of Pressure Relief ValveOverview of Pressure Relief Valve
Overview of Pressure Relief Valve
 
Piston pumps
Piston pumpsPiston pumps
Piston pumps
 
Fundamentals of Centrifugal Compressor - Head (revised)
Fundamentals of Centrifugal Compressor - Head (revised)Fundamentals of Centrifugal Compressor - Head (revised)
Fundamentals of Centrifugal Compressor - Head (revised)
 

Similar to 2 pumps part 2 including centrifugal pumps rev 4

Design of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic couplingDesign of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic coupling
ijmech
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
fdhjsekdme
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
jfjkskekfsielkm
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
udfjjjsekkmem
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
fusjefjkskem
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
fjsiefkkskemm
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
ufjjdfkkskemm
 
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
fusjezsfkskefmsme
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
cdsaas
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
hhfjksekmm
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
fjskekxcddmmme
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
hhfjksekmm
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
fjskekxcddmmme
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
cdsaas
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
fjkskekdmmenm
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
ujjdjjkksmmd
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
fujsefkskekmm
 

Similar to 2 pumps part 2 including centrifugal pumps rev 4 (19)

Design of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic couplingDesign of quick connect disconnect hydraulic coupling
Design of quick connect disconnect hydraulic coupling
 
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINEDESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
DESIGN AND ANALYSIS OF ELECTRO HYDRAULIC THRUSTER BRAKE FOR LIFTING MACHINE
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
Caterpillar cat 320 d2 excavator (prefix xbb) service repair manual (xbb00001...
 
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
Caterpillar cat 249 d compact track loader (prefix gwr) service repair manual...
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
 
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
Caterpillar cat 349 e l excavator (prefix etc) service repair manual (etc0000...
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
 
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
Caterpillar cat 349 e l vg excavator (prefix etc) service repair manual (etc0...
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
 
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
Caterpillar cat 973 c track loader (prefix bcp) service repair manual (bcp000...
 

Recently uploaded

Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills KuwaitKuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
jaanualu31
 
Online food ordering system project report.pdf
Online food ordering system project report.pdfOnline food ordering system project report.pdf
Online food ordering system project report.pdf
Kamal Acharya
 
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments""Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
mphochane1998
 
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
Health
 
Integrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - NeometrixIntegrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - Neometrix
Neometrix_Engineering_Pvt_Ltd
 
notes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.pptnotes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.ppt
MsecMca
 

Recently uploaded (20)

Bridge Jacking Design Sample Calculation.pptx
Bridge Jacking Design Sample Calculation.pptxBridge Jacking Design Sample Calculation.pptx
Bridge Jacking Design Sample Calculation.pptx
 
DC MACHINE-Motoring and generation, Armature circuit equation
DC MACHINE-Motoring and generation, Armature circuit equationDC MACHINE-Motoring and generation, Armature circuit equation
DC MACHINE-Motoring and generation, Armature circuit equation
 
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptxS1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
 
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
 
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills KuwaitKuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
 
Work-Permit-Receiver-in-Saudi-Aramco.pptx
Work-Permit-Receiver-in-Saudi-Aramco.pptxWork-Permit-Receiver-in-Saudi-Aramco.pptx
Work-Permit-Receiver-in-Saudi-Aramco.pptx
 
FEA Based Level 3 Assessment of Deformed Tanks with Fluid Induced Loads
FEA Based Level 3 Assessment of Deformed Tanks with Fluid Induced LoadsFEA Based Level 3 Assessment of Deformed Tanks with Fluid Induced Loads
FEA Based Level 3 Assessment of Deformed Tanks with Fluid Induced Loads
 
Unleashing the Power of the SORA AI lastest leap
Unleashing the Power of the SORA AI lastest leapUnleashing the Power of the SORA AI lastest leap
Unleashing the Power of the SORA AI lastest leap
 
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptxHOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
 
Online food ordering system project report.pdf
Online food ordering system project report.pdfOnline food ordering system project report.pdf
Online food ordering system project report.pdf
 
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments""Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
 
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
+97470301568>> buy weed in qatar,buy thc oil qatar,buy weed and vape oil in d...
 
Minimum and Maximum Modes of microprocessor 8086
Minimum and Maximum Modes of microprocessor 8086Minimum and Maximum Modes of microprocessor 8086
Minimum and Maximum Modes of microprocessor 8086
 
data_management_and _data_science_cheat_sheet.pdf
data_management_and _data_science_cheat_sheet.pdfdata_management_and _data_science_cheat_sheet.pdf
data_management_and _data_science_cheat_sheet.pdf
 
Integrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - NeometrixIntegrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - Neometrix
 
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptxCOST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
 
kiln thermal load.pptx kiln tgermal load
kiln thermal load.pptx kiln tgermal loadkiln thermal load.pptx kiln tgermal load
kiln thermal load.pptx kiln tgermal load
 
Rums floating Omkareshwar FSPV IM_16112021.pdf
Rums floating Omkareshwar FSPV IM_16112021.pdfRums floating Omkareshwar FSPV IM_16112021.pdf
Rums floating Omkareshwar FSPV IM_16112021.pdf
 
notes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.pptnotes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.ppt
 
Online electricity billing project report..pdf
Online electricity billing project report..pdfOnline electricity billing project report..pdf
Online electricity billing project report..pdf
 

2 pumps part 2 including centrifugal pumps rev 4

  • 1. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / / Rev 2 ACADBasics@gpworldwide.com ACAD BASIC CURRICULUM MECHANICAL SCIENCE Chapter 2 Part 2 – Centrifugal Pumps PISTON ROD VALVE VALVE VALVE PISTON PACKING PISTON DISCHARGE MANIFOLD SUCTION MANIFOLD PISTON-ROD PACKING MOTION SUCTION PIPE DISCHARGE PIPE PISTON ROD VALVE VALVE VALVE VALVE PISTON PACKING PISTON DISCHARGE MANIFOLD SUCTION MANIFOLD PISTON-ROD PACKING MOTION SUCTION PIPE DISCHARGE PIPE VALVE IMPELLER WEARING RINGINLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING
  • 2. © 2003 General Physics Corporation PUMP CLASSIFICATIONS PUMPS Kinetic (Dynamic) Positive Displacement Part 1 Part 2
  • 3. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 2 / Rev 02 OBJECTIVES 12. STATE the purpose of the following centrifugal pump components: a. Casing e. Bearings b. Gaskets f. Seal rings c. Impeller g. Volute d. Shaft h. Shaft seals 13. DESCRIBE the operation of the following types of centrifugal pumps: a. Volute and diffuser pumps b. Radial-flow, axial-flow and mixed-flow pumps 14. DESCRIBE the operation of centrifugal pumps, including requirements for the following: a. NPSH b. Starting a centrifugal pump c. Operation with a centrifugal pump dead headed d. Minimum flow e. Prevention of runout Part 2 has 12 objectives.
  • 4. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 3 / Rev 02 OBJECTIVES 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. 16. EXPLAIN the three centrifugal pump laws. 17. DETERMINE the effects of changes for a centrifugal pump in flow, pump speed, or system characteristic curve on the system operating point. 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention. 19. DRAW and LABEL characteristic curves for centrifugal pumps.
  • 5. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 4 / Rev 02 OBJECTIVES 20. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: a. One pump in slow speed b. One pump in fast speed c. Two pumps in parallel d. Two pumps in series 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. 22. DESCRIBE the operation of jet pumps. 23. DESCRIBE what items are included in post maintenance testing. 24. IDENTIFY and DESCRIBE auxiliary support equipment associated with pumps. [Not included in Mechanical Technology I]
  • 6. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 5 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Most common pump used in industry.
  • 7. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 6 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 • Centrifugal force is the outward force. • Centrifugal pumps turn kinetic energy into flow energy (pressure). • Wide range of pressures and flow rates. • Basic process:  Shaft (driven by motor)  Fluid enters the suction eye  Impeller pushes the water and increases its speed  Water moves outward moving very fast  The volute widens and KE is turned into pressure.
  • 8. © 2003 General Physics Corporation CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Objective 12. STATE the purpose of the following centrifugal pump components: a. Casing b. Gaskets c. Impeller d. Shaft e. Bearings f. Seal rings g. Volute h. Shaft seals
  • 9. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 8 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 8 major components of a centrifugal pump: • Casing • Gaskets • Impeller • Shaft • Bearings • Seal rings • Volute • Shaft seals Objective 12
  • 10. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 9 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The pump casing houses the majority of the major pump components. • The inlet (suction) and outlet (discharge) connections are integral to the pump casing. Objective 12a
  • 11. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 10 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The faces of the casing are machined to fit together smoothly, but the finest machining still has some leakage. Objective 12a
  • 12. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 11 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Casing • The faces of the casing are machined to fit together smoothly, but the finest machining still has some leakage. • Gaskets are used to reduce leakage • Gaskets are semi-soft flexible materials used to seal mating surfaces or flanges. Objective 12ab
  • 13. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 12 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Impeller • The impeller is the rotating component of the pump that converts the mechanical energy of the prime mover (the pump motor) into kinetic energy (velocity) in the fluid. • The impeller is mounted on the pump Shaft. Objective 12c
  • 14. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 13 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Shaft • The shaft connects the prime mover to the impeller. • This may be done either directly or through a flexible coupling. • The function of the pump shaft is to transmit the torque from the prime mover to the impeller. Objective 12d
  • 15. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 14 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Bearings • The shaft is supported by bearings. • Bearings provide two types of support, radial support for side to side motion and axial support for movement along the axis. Objective 12e
  • 16. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 15 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Bearings • The radial support is provided by antifriction journal bearings. • The bearings that provide the axial support are called thrust bearings. Objective 12e
  • 17. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 16 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Seal rings • The casing rings and wearing rings provide the seal needed between the impeller and the casing. • This seal prevents high-pressure discharge water from leaking back to the low pressure suction side of the impeller. Objective 12f
  • 18. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 17 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Seal rings • The wearing rings also prevent excessive wearing (erosion) of the pump casing. • The casing ring fits into the casing and the wearing ring fits onto the impeller and rotates with it. Objective 12f
  • 19. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 18 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Volute • The volute is a gradually expanding spiral that is integral to the casing. • It reduces fluid velocity and increases fluid pressure. Objective 12g
  • 20. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 19 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 Shaft seals • In almost all centrifugal pumps, the rotating shaft that drives the impeller penetrates the pressure boundary of the pump casing. Objective 12h
  • 21. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 20 / Rev 02 CENTRIFUGAL PUMP IMPELLER WEARING RING INLET LANTERN RINGPACKING STUFFING BOX GLAND SHAFT JOURNAL BEARING STUFFING BOX (INTEGRAL WITH CASING) LIQUID SEAL SUPPLY THROAT BUSHING CASING VOLUTE IMPELLER THRUST BEARING OUTLET CASING WEARING RING Fig 2-29 8 major components of a centrifugal pump: Shaft seals • There are many different methods of sealing the shaft penetration of the pump casing. Objective 12h
  • 22. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 21 / Rev 02 OPEN IMPELLER Fig 2-30 • Vanes always “sling” the water out. • They do not “dig in”. • If installed backwards or if the prime mover rotates in reverse, the pump will operate at a significantly reduced capacity. • The open impeller consists only of blades attached to a hub. • Open impellers are good for pumping liquids containing solids because they do not clog. PUMP ROTATION
  • 23. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 22 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller
  • 24. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 23 / Rev 02 SEMI-CLOSED IMPELLER PUMP ROTATION Fig 2-31 • Semi-enclosed impellers are more efficient than the open impeller. • The design also enables the impeller to move water against greater backpressure.
  • 25. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 24 / Rev 02 CLOSED IMPELLER Fig 2-32 • Although it is more expensive, the closed impeller is more efficient than the open impeller. • It also offers the advantage of reduced wear due to less erosion of the impeller vanes. • This pump performance remains consistent throughout pump life.
  • 26. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 25 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction
  • 27. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 26 / Rev 02 SINGLE-SUCTION IMPELLER C. RADIAL VIEW OF PUMP B. CROSS-SECTION VIEW OF IMPELLER OUT SHAFT IN IN OUT A. ANGLE VIEW OF IMPELLER IN IN OUT OUT OUT PUMP INTAKE WEARING RING IMPELLER CASING STUFFING BOX OR PACKING GLAND Fig 2-34 Thrust Force
  • 28. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 27 / Rev 02 DOUBLE-SUCTION IMPELLER (A) ANGLE VIEW OF DOUBLE- SUCTION IMPELLER IN IN IN IN OUT (B) CROSS SECTION OF THE IMPELLER IN IN IN IN OUT OUT (C) CROSS SECTION OF THE PUMP IMPELLERWEARING RING STUFFING BOX SHAFT CASING Fig 2-35 Thrust force is eliminated.
  • 29. © 2003 General Physics Corporation CENTRIFUGAL PUMP Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction. • Vertical or horizontal
  • 30. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 29 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction • Vertical or horizontal • Single-stage, double-stage, or multi- stage
  • 31. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 30 / Rev 02 FLOW THROUGH A MULTI-STAGE PUMP SUCTION IMPELLERS DISCHARGE SHAFT BALANCING LINE HIGH PRESSURE LOW PRESSURE AXIAL THRUST BALANCING DRUM SHAFT SUCTION IMPELLERS DISCHARGE SHAFT BALANCING LINE HIGH PRESSURE LOW PRESSURE AXIAL THRUST BALANCING DRUM SHAFT Fig 2-36 • Each impeller is considered to be a "pressure stage".
  • 32. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 31 / Rev 02 MULTI-STAGE SINGLE AND DOUBLE SUCTION IMPELLER FLOW PATH DOUBLE ADMISSION SINGLE ADMISSION ADMISSION DISCHARGE DISCHARGE ADMISSION Fig 2-37
  • 33. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 32 / Rev 02 CENTRIFUGAL PUMP DISCHARGE IMPELLER VANES EYE Fig 2-29 Centrifugal pumps are classified by design features: • Closed, open, or semi-open impeller • Single-suction or double-suction. • Vertical or horizontal • Single-stage, double-stage, or multi- stage • Volute or diffuser
  • 34. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 33 / Rev 02 VOLUTE AND DIFFUSER PUMPS VOLUTE DIFFUSER ROTATING IMPELLER STATIONARY DIFFUSER VANES Objective 13a. DESCRIBE the operation of the following types of centrifugal pumps: Volute and diffuser pumps
  • 35. © 2003 General Physics Corporation DIFFUSER CENTRIFUGAL PUMPS • In diffuser pumps, the volute is enhanced with a diffuser and a series of stationary vanes arranged around the impeller. 1) The purpose of the diffuser is to increase the efficiency of the centrifugal pump by straightening the flow in the volute. a) This reduces turbulence and allows a more gradual conversion of velocity head to pressure head. 2) Since the vanes are farther apart at their outermost points than at the edge of the impeller, they create a series of widening chambers that convert kinetic energy into pressure in the same way that a volute does. 3) The diffuser vane helps balance the radial thrust loads on the impeller, shaft, and journal bearings for varying flow conditions. Objective 13a
  • 36. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 35 / Rev 02 PACKING SEALS Fig 2-42 PACKING GLAND STUFFING BOX LIQUID SEAL SUPPLY SHAFT LANTERN RING PACKING There must be a seal where the shaft penetrates the casing to prevent the pumped fluid from leaking out around the rotating shaft. • This is accomplished with a shaft seal. • A shaft seal can be a stuffing box or a mechanical seal.
  • 37. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 38 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 Objective 13b. DESCRIBE the operation of the following types of centrifugal pumps: Radial-flow, axial-flow and mixed-flow pumps
  • 38. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 39 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 • By radically changing the direction of flow and directing the fluid through a volute, radial-flow pumps are able to create a high discharge pressure.
  • 39. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 40 / Rev 02 RADIAL-FLOW AND AXIAL-FLOW PUMPS CASING PUMP SHAFT IMPELLER (PROPELLER) AXIAL-FLOW FLOWCASING FLOW IMPELLER RADIAL-FLOW Fig 2-40 • In contrast, axial-flow pump can move tremendous volumes of fluid • but at relatively low discharg pressures.
  • 40. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 41 / Rev 02 MIXED-FLOW PUMP SUCTION SHAFT VOLUTE DISCHARGE IMPELLER VANE SUCTION SHAFT VOLUTE DISCHARGE IMPELLER VANE Fig 2-41 • Mixed-flow pumps combine, to some degree, the functions of radial-flow pumps and axial flow pumps.
  • 41. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 42 / Rev 02 Centrifugal Pump Operation Objective 14b. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Starting a centrifugal pump RECIRC LINE PUMP CHECK VALVE DISCHARGE VALVE SUCTION VALVE VENT VALVE DRAIN VALVE
  • 42. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 43 / Rev 02 Centrifugal Pump Operation Fig 2-56 Objective 14b. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Starting a centrifugal pump • A centrifugal pump is not self priming and requires adequate net positive suction head (NPSH) to prevent cavitation. • There are two reasons for closing the discharge valve: First, it minimizes the chances of pump runout. [Objective 14e and 18] Second, it prevents backflow through the pump that can result in abnormally high starting currents, which could damage the motor windings. Fig 2-57
  • 43. © 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • Many centrifugal pumps are designed to operate continuously for months or even years. • Closing the pump discharge valve while the pump is still operating stops flow through the pump and the pump will no longer be adequately cooled. • Pump damage can also result from pumping a liquid whose temperature is close to saturated conditions. • Overheating will occur if a pump is operated against a closed valve (dead headed) for more than a few minutes. Objective 14c. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Operation with a centrifugal pump dead headed.
  • 44. © 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • This is called operating at shutoff head. • Shutoff head is generally defined as the maximum value of head that a pump can produce. • Operating a centrifugal pump with the discharge valve closed is also called dead heading the pump. • Because the fluid in the pump has no where to go the spinning impeller heats the fluid. • This has two disastrous results. Objective 14c. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Operation with a centrifugal pump dead headed.
  • 45. © 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING • This has two disastrous results. 1) Heat from the heated fluid is transferred to the internal pump components. a) This can cause damage to bearings and components with close tolerances. b) The casing and wearing rings may expand from the heat and come in contact with one another. 2) Secondly, the heated fluid may reduce the net positive suction head available by raising the temperature of the fluid to a saturated temperature. a) As the fluid reaches saturated temperature it also reaches saturation pressure. b) This can result in cavitation of the pump and severe and rapid damage. Objective 14a. NPSH.
  • 46. © 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING In many applications, a bypass or minimum flow line prevents the pump from operating at shutoff head. • With these modifications, an amount of flow necessary to cool the pump can be maintained. • The smallest amount of flow that prevents overheating is called the pump minimum flow requirement. Objective 14d. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Minimum flow. Fig 2-57
  • 47. © 2003 General Physics Corporation CENTRIFUGAL PUMP COOLING In many applications, a bypass or minimum flow line prevents the pump from operating at shutoff head. Objective 14d. DESCRIBE the operation of centrifugal pumps, including requirements for the following: Minimum flow. RECIRC LINE PUMP CHECK VALVE DISCHARGE VALVE SUCTION VALVE VENT VALVE DRAIN VALVE Fig 2-57
  • 48. © 2003 General Physics Corporation CENTRIFUGAL PUMP LAW EQUATIONS Objective 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. Objective 16. EXPLAIN the three centrifugal pump laws. These laws state that a. the volumetric flow rate or capacity is directly proportional to the pump speed, b. the discharge head (pressure) is directly proportional to the square of the pump speed, and c. the power required by the pump motor is directly proportional to the cube of the pump speed.
  • 49. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 50 / Rev 02 CENTRIFUGAL PUMP LAWS Where: = pump volumetric flow rate (m3/s, m3/min, m3/hr)  = proportional N = pump speed (rpm) Hp = pump discharge head (Pa) P = pump power (W) NV  Hp  N2 P  N3 V Eq 2-14 flow pump load power
  • 50. © 2003 General Physics Corporation CENTRIFUGAL PUMP LAW EQUATIONS Where: = initial pump speed = proportional 2 1 2 1 V )N( )N( V   p22 1 2 2 p1 H )(N )(N H  23 1 3 2 1 P )N( )N( P  N1 N2 Objective 15. STATE the relationship between pump load, motor current, speed, flow, pressure, and power for a centrifugal pump. Objective 16. EXPLAIN the three centrifugal pump laws. flow pump load power
  • 51. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 52 / Rev 02 EXAMPLE 2-17 A regulating water pump is operating at 1,000 rpm. Its capacity is 50.0 m3/hour at a discharge head of 70 kPa that requires a power of 50 kW. Determine the pump capacity, discharge head, and power requirements if the pump speed is increased to 2,000 rpm. Ex 2-17
  • 52. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 53 / Rev 02 EXAMPLE 2-17 (continued) The pump speed is increased by a factor of two; therefore, the capacity is increased by a factor of two. Using the equation for capacity: Ex 2-17
  • 53. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 54 / Rev 02 EXAMPLE 2-17 (continued) If the pump speed is increased by a factor of two, the discharge head is increased by a factor of two squared. Using the equation for discharge head: Ex 2-17 p22 1 2 2 p1 H )(N )(N H 
  • 54. © 2003 General Physics Corporation EXAMPLE 2-17 (continued) If the pump speed is increased by a factor of two, the power requirement is increased by a factor of two cubed. Using the equation for power:
  • 55. © 2003 General Physics Corporation CENTRIFUGAL PUMP CHARACTERISTICS Objective 17. DETERMINE the effects of changes for a centrifugal pump in flow, pump speed, or system characteristic curve on the system operating point. One of the most important characteristics of a pump is its capacity, or how much fluid it moves per unit time. • The capacity of a centrifugal pump decreases as the pressure at the pump discharge increases. • At a particular pressure, called the shutoff head, the pump moves no fluid at all. • A plot for a centrifugal pump that shows discharge head versus capacity for a given pump speed is often called the pump characteristic curve. Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention [Objective 14e].
  • 56. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 57 / Rev 02 CENTRIFUGAL PUMP CHARACTERISTIC CURVE Fig 2-44 CAPACITY (m3/h  435) DISCHARGEHEAD(mx3.3) 0 0.25 0.5 0.75 1 1.25 1. 1.75 2.0 60 54 48 42 36 30 24 18 12 6 0 PUMP SHUTOFF HEAD PUMP RUNOUT Objective 19. DRAW and LABEL characteristic curves for centrifugal pumps.
  • 57. © 2003 General Physics Corporation Effects at Shutoff Head Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention. At shutoff head (also called “dead-headed”) the pump is producing the maximum value of discharge head. However, a pump can only operate at shutoff head for only a few minutes. • The resulting friction increases pump and fluid temperature. • Overheating of the pump may occur at this point.
  • 58. © 2003 General Physics Corporation Effects at Runout • Runout, an abnormally high flow rate from a centrifugal pump, can lead to mechanical stress on the pump and excessive motor current. • If the pump discharges directly to the atmosphere, the pump capacity is at its maximum. • Runout is the result of a loss of downstream pressure (piping not filled and vented, leak or pipe break). • The drop in pressure speeds up the pump and causes excessive motor current, which may result in damage to the windings. • The low backpressure can also result in cavitation and excessive flow. Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention.
  • 59. © 2003 General Physics Corporation Prevention of Runout • To help prevent runout, ensure proper venting and filling of systems before pump startup. • High motor current trips protect pump motors from winding damage due to runout. • Limit the flow (“One method for ensuring that there is always adequate flow resistance at the pump discharge to prevent excessive flow through the pump is to place an orifice or a throttle valve immediately downstream of the pump discharge. Properly designed piping systems are very important to protect from runout.”) Objective 18. DESCRIBE pump shutoff head and runout, including definitions, causes, effects on centrifugal pump operation, and methods of prevention [Objective 14e].
  • 60. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 61 / Rev 02 EFFECT OF DOUBLING CENTRIFUGAL PUMP SPEED Fig 2-45 Objective 20. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: a. One pump in slow speed b. One pump in fast speed c. Two pumps in parallel d. Two pumps in series • Based on the pump laws previously discussed, if the pump speeds up, the entire characteristic curve moves outward, away from the origin. • The pump capacity increases by the same factor as the speed increases, and the pump discharge head increases as the square of the factor by which the speed increases.
  • 61. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 62 / Rev 02 EFFECT OF DOUBLING CENTRIFUGAL PUMP SPEED Fig 2-45 CAPACITY (m3/h x 435) DISCHARGEHEAD(mx3.3) 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 220 214 208 202 196 190 182 176 170 164 158 152 146 140 134 128 122 116 110 104 98 90 84 78 72 66 60 54 48 42 36 30 24 18 12 6 0 Objective 20a,b • If the pump operates at constant efficiency, the power required to operate the pump at a new speed increases as the cube of the factor by which the speed increases. • However, pump efficiency varies widely over an operating range and with speed as well.
  • 62. © 2003 General Physics Corporation CENTRIFUGAL PUMP CHARACTERISTIC CURVES 0 25 75 125 CAPACITY (m3/h x 435) 40 50 30 20 0 10 DISCHARGEHEAD(mx3.3) 80 100 60 40 0 20 EFFICIENCY(%) PUMP CHARACTERISTIC EFFICIENCY CURVE SYSTEM OPERATING CURVE OPERATING POINT Fig 2-46
  • 63. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 64 / Rev 02 CENTRIFUGAL PUMP CHARACTERISTIC CURVES 0 25 75 125 CAPACITY (m3/h x 435) 60 0 40 POWER(HP) 80 20 0 25 75 125 CAPACITY (m3/h x 435) 40 50 30 20 0 10 DISCHARGEHEAD(mx3.3) 80 100 60 40 0 20 EFFICIENCY(%) PUMP CHARACTERISTIC EFFICIENCY CURVE SYSTEM OPERATING CURVE OPERATING POINT Fig 2-46
  • 64. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 65 / Rev 02 HEAD vs. FLOW FOR A CENTRIFUGAL PUMP PUMPHEAD(FEET) VOLUMETRIC FLOW RATE NEW OPERATING POINT VALVE PARTIALLY SHUT VALVE OPEN INITIAL OPERATING POINT SYSTEM OPERATING CURVES Fig 2-47
  • 65. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 66 / Rev 02 CENTRIFUGAL PUMPS IN PARALLEL PUMP CHECK VALVE Fig 2-48 Objective 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. • This type of configuration is useful when the demand for volume fluctuates. • One pump can be operated when the demand is low, and the second pump can be started and used when the fluid flow requirement increases beyond the capacity of the first pump. • This arrangement also provides system component redundancy and backup.
  • 66. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 67 / Rev 02 PUMP CURVES FOR IDENTICAL CENTRIFUGAL PUMPS IN SINGLE AND PARALLEL OPERATION Fig 2-49 PUMPS A and B 4” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY ( m3/h x 435) 30 35 40 2 1 Objective 20c. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: Two pumps in parallel.
  • 67. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 68 / Rev 02 SINGLE CENTRIFUGAL PUMP OPERATION WITH SYSTEM VARIATION Fig 2-52 PUMPS A and B 4” pipe 5” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY (m3/h x 435) 30 35 40 1 2
  • 68. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 69 / Rev 02 CENTRIFUGAL PUMPS IN PARALLEL WITH SYSTEM VARIATIONS Fig 2-53 PUMPS A and B 4” pipe 5” pipe PUMP A or B 40 35 30 20 25 15 10 0 5 TOTALHEAD(mx3.3) 0 5 10 15 20 25 CAPACITY (m3/h x 435) 30 35 40 1 3 2 4
  • 69. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 70 / Rev 02 CENTRIFUGAL PUMPS IN SERIES Fig 2-54 Objective 21. DESCRIBE the operation of centrifugal pumps in series and in parallel arrangements. Objective 20d. DESCRIBE the shape of the characteristic curves for the following centrifugal pump operating modes: Two pumps in series.
  • 70. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 71 / Rev 02 CENTRIFUGAL PUMPS IN SERIES CHARACTERISTIC CURVES Fig 2-55 48 36 24 0 6 0 5 10 15 20 25 TOTALHEAD(mx3.3) PUMP A plus B 72 60 12 30 CAPACITY (m3/h x 435) PUMP A or B SYSTEM OPERATING CURVE • For an efficient unit, capacities at best efficiencies for the individual pumps should be about the same.
  • 71. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 72 / Rev 02 OPEN SYSTEM CHARACTERISTIC CURVES FOR CENTRIFUGAL PUMPS Fig 2-56 PUMPHEAD(FEET) VOLUMETRIC FLOW RATE NEW OPERATING POINT VALVE PARTIALLY SHUT VALVE OPEN INITIAL OPERATING POINT PUMP CHARACTERISTIC CURVE Static Head SYSTEM OPERATING CURVES • While some aspects of Open System operation are similar to Closed System operation, other aspects are completely different. • Most notably, the pump laws DO NOT APPLY to open system situations in which the system inlet and discharge points are at different pressures or elevations.
  • 72. © 2003 General Physics Corporation CENTRIFUGAL PUMP OPERATION • 1. Line up auxiliary items. • 2. Open the pump suction valve. • 3. Prime the pump. • 4. Shut the pump discharge valve, or verify • that it is shut. • 5. Start the pump motor. • 6. Slowly open the pump discharge valve. ABC / Mechanical Science / Chapter 2 / TP 2 - 73 / Rev 02
  • 73. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 74 / Rev 02 EDUCTOR CONSTRUCTION CONDENSER GASES AND VAPORS TO BE COMPRESSED SUCTION CHAMBER STEAM STEAM NOZZLE CONVERGENT DIFFUSER NOZZLE DIFFUSER DIVERGENT DIFFUSER NOZZLE STRAIGHT THROAT Fig 2-58 Objective 22. DESCRIBE the operation of jet pumps.
  • 74. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 75 / Rev 02 EDUCTOR CONSTRUCTION Fig 2-58 • Jet pumps are static (static in this use means no moving parts) devices that convert high pressure driving flow developed by an external source into a high velocity jet flow at low pressure. • The fluid to be moved surrounds the high velocity jet. • The benefits of this pump are low maintenance, high reliability, and small size when compared with other pumps of the same capacity. • A disadvantage is the need for a high pressure supply to develop the required high head for the driving flow. Objective 22. DESCRIBE the operation of jet pumps.
  • 75. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 76 / Rev 02 MACH NUMBER EQUATION Where: Nm = Mach number V = velocity of mixture C = sonic velocity for the given material and conditions C V Nm  Eq 2-16
  • 76. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 77 / Rev 02 MACH NUMBER EQUATION (cont’d) Nm < 1 subsonic Nm = 1 sonic Nm > 1 supersonic Eq 2-16
  • 77. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 78 / Rev 02 STEAM JET AIR EJECTOR STEAM ONLY AIR ONLY STEAM & AIR MIXTURE MACH 1 VELOCITY SUPERSONIC VELOCITY SUBSONIC VELOCITY SONIC VELOCITY CONDENSER GAS & VAPORS TO BE COMPRESSED SUCTION CHAMBER STEAM STEAM NOZZLE DIVERGENT DIFFUSER NOZZLE STRAIGHT THROAT STEAM & AIR DISCHARGE DIFFUSER CONVERGENT DIFFUSER NOZZLE STEAM & AIR DISCHARGE PRESSURE CONDENSER VACUUM PRESSURE STEAM PRESSURE STEAM EJECTOR OPERATING STEAM PRESSURE Fig 2-59
  • 78. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 79 / Rev 02 JET PUMP OPERATING PRINCIPLES Fig 2-60 PRESSURE SUCTION FLOW DRIVING FLOW (1/3) SUCTION OR DRIVEN FLOW (2/3) DRIVING FLOW DP DRIVING FLOW PRESSURE THROAT OR MIXING SECTION SUCTION FLOW DP PRESSURE DISTANCE DIFFUSER DRIVING NOZZLE
  • 79. © 2003 General Physics Corporation POST MAINTENANCE TESTING Objective 23. DESCRIBE what items are included in post maintenance testing. Post-maintenance tests can include: • Leakage tests to verify the leakage past shaft seals are within the specification for that pump and its application. • Verification of pump responses to automatic initiation and trip signals. • Flow verification to ensure the pump is capable of delivering the required flow and pressure. • Hydrostatic testing to ensure all connections are capable of withstanding the normal operating conditions to which the pump will be exposed. • Vibration testing to ensure the pump shaft alignment and component installation has been performed correctly and to establish base line data for future testing of the pump.
  • 80. © 2003 General Physics Corporation POST MAINTENANCE TESTING Objective 24. IDENTIFY and DESCRIBE auxiliary support equipment associated with pumps. Not covered in course material, so it will not be covered on the Final Examination.
  • 81. © 2003 General Physics Corporation ABC / Mechanical Science / Chapter 2 / TP 2 - 82 / Rev 02 OBJ QUESTIONS & ANSWERS