1. Danilo V. Ravina, NAMPAP CEBU 1
MODULE 7:
THE PUMPING OF WATER
PLUMBING FUNDAMENTALS
2. Danilo V. Ravina, NAMPAP
CEBU
2
What are the Factors to be considered in the
Pumping of Water?
1. The Mass of the water to be lifted.
2. The Height through which water must be lifted or
forced.
3. The Distance water must travel in flowing from one
place to another.
4. The ways in which water may be affected by
Friction.
3. Danilo V. Ravina, NAMPAP
CEBU
3
The Elements of Pumping of Water:
Mass of
Water
Height
of
Water
Travel Distance
Pipe Friction
4. Danilo V. Ravina, NAMPAP
CEBU
4
What are the different types of Heads relative to
the pumping of water?
• Pressure in a water supply system is dependent on the head of water
above the point being considered.
• There are different kinds of Head defined according to their effect on
pumping operations:
1. Static Discharge Head 10. Static Suction Lift
2. Friction Head 11. Total Suction Lift
3. Total Discharge Head 12. Negative Suction Lift
4. Suction Head 13. Total Negative Suction
5. Positive Suction Head Lift
6. Velocity Head
7. Total Positive Suction Head
8. Pressure Head
9. Total Pump Head
5. Danilo V. Ravina, NAMPAP CEBU 5
• Total Delivery Head-is the Static Delivery Head
+ the Friction Head in all of the delivery pipe &
fittings.
• Static Delivery Head-is the vertical distance
from the center line of the pump to the point of
free discharge (free surface of the discharge
liquid).
• Friction Head-is the head necessary to
overcome resistance to flow of the liquid. Friction
head must not exceed the TDH.
• Static Suction Lift –is the vertical distance from
the liquid level to the center line of the pump.
• Velocity Head-is the head required to accelerate
the water in the delivery pipe. It is so nominal
that it is usually ignored.
• Total Pump Head-is the Total Suction Lift + Total
Delivery Head + the Velocity Head.
Various Pumping Heads
6. Danilo V. Ravina, NAMPAP CEBU 6
• Negative Suction Lift – exists when the pump is
above the liquid to be pumped & is the vertical
distance from the centerline of the pump down to
the free surface of the liquid.
• Pressure Head – is the vertical height to which a
given pressure will force water. If the pressure is
known the head can be calculated as:
Head (m) = Pressure (kPa) x 0.102
• Total Suction Lift – is the Static Suction Lift +
Friction Head in the entire suction pipe & fittings.
• Suction Lift – is the term used when the source
of supply is below the center line of the pump.
• Total Negative Suction Lift – is the Static
Suction Lift + the Friction Lift & the Velocity Head
in the inlet pipe system.
Pumping Liquid with
Negative Suction Lift
7. Danilo V. Ravina, NAMPAP CEBU 7
• Positive Suction Head – exists when the
pump is below the liquid to be pumped &
is the vertical distance from the centerline
of the pump to the free surface of the
liquid.
• Total Positive Suction Head – is the
Static Suction Head minus the Friction
Head and the Velocity Head in the inlet
pipe system.
8. Danilo V. Ravina, NAMPAP
CEBU
8
What is the common system of pumping water
in high rise buildings:
The Overhead Feed System
1. Composed of a low level cistern (suction tank) that receives water from
the supply main at the ground level and serves as a boosting reservoir &
prevents the lowering of pressure on the supply main. The sizing of the
suction tank should be carefully considered to prevent water
stagnation, which could occur because of oversizing.
2. A Gravity tank is installed at the topmost part of the building to get the
required head for the downfeed pipe.
3. A Transfer pump is used as a boosting equipment to bring water from
the suction tank to the gravity tank, while overcoming the total static
head plus the frictional resistances in the pipes and fittings.
9. Danilo V. Ravina, NAMPAP
CEBU
9
The Overhead Feed System
Gravity Tank
Transfer
Pump
Suction Tank
Upfeed
Pipe
or
Supply
Riser
Suction Tank
10. Danilo V. Ravina, NAMPAP
CEBU
10
Variations of the Overhead Feed Piping System:
SINGLE STAGE PUMPING FOR MID-RISE BUILDINGS
11. Danilo V. Ravina, NAMPAP
CEBU
11
Variations of the Overhead Feed Piping System:
SINGLE STAGE PUMPING FOR MID-RISE BUILDING
12. Danilo V. Ravina, NAMPAP
CEBU
12
Variations of the Overhead Feed Piping System:
ZONED PUMPING FOR HIGH RISE BUILDINGS
13. Danilo V. Ravina, NAMPAP
CEBU
13
What is Hydropneumatic Pressure System?
• The topmost floor of the building may not have the available
working pressure for the plumbing fixtures contained therein
due to lack of the required head.
• To compensate for this deficiency, a hydropneumatic system is
provided to raise and supply water to these fixtures, using
compressed air as the delivering agent.
• This system is composed of double-acting reciprocating pump
and a cylindrical steel storage tank.
• In multi storey buildings, hydropneumatic pressure systems
serve zones of about 10 storeys. A thirty storey building may
be provided with 3 distinct units, each providing water supply
at every 10 floor interval.
14. Danilo V. Ravina, NAMPAP CEBU 14
Operating Principle of Hydropneumatic Pressure System:
• The pressure tank is normally
filled with water in the lower part
& air in the upper part.
• The water is pumped into the
tank near the bottom,
compressing the air above it.
• The usual pressure range is 138
kPa (20 psi) minimum to 276 kPa
(40 psi) maximum.
• When the pressure is at
minimum, the pump starts and if
the pressure reaches maximum, it
stops.
15. Danilo V. Ravina, NAMPAP
CEBU
15
What are the kinds of Pressure Vessels used in the
Hydropneumatic Pressure System?
1. Simple Air Cushion Tank – a tank constructed to special standards
to withstand pressure. It is usually coated inside with corrosion
resistant treatment as the water makes direct contact with the interior.
The air is compressed above the water.
2. Separated Air Cushion Cylinder – water is totally confined in an
elastic rubber bag. When water is pumped the bag expands,
compressing the air in the cylinder until the pressure switch reaches its
setting & shuts off the motor. When a faucet is opened the compressed
air forces the water out & the pressure drops until the switch again
starts the motor. The air is never in contact with the water, so it cannot
be absorbed.
3. Elastic Sock Pressure Vessel – uses a very strong rubber “sock”
which is stretched by the water pressure & then forces the water out
when a faucet is opened. The capacity of this type is much less than
the air cushion & therefore the water will turn on more often causing
faster wear and tear.
16. Danilo V. Ravina, NAMPAP
CEBU
16
Pumping of Potable and Non-Potable Water
