2. 1.0.0 Introduction
• Valves are devices that control the flow of
fluids or gases through a piping system.
• Valves are made of a wide variety of materials
for compatibility to the fluid flowing through
it.
3. 2.0.0 Valves That Start and Stop Flow
• These valves are designed to be operated completely
open or completely closed.
• These valves cannot be used effectively to throttle, or
regulate, flow.
• Gate Valve
• Knife Valve
• Ball Valve
• Plug Valve
• Three-Way Valve
4. 2.1.0 Gate Valve
• Turning the hand-wheel lifts or lowers the disc
(gate).
• A partially opened gate causes turbulence.
• This turbulence not only causes piping
damage (water hammer), it also wears the
disc and seat surfaces.
5. 2.1.0 Gate Valve – Solid Wedge
Most common used:
a single, solid disc
that is rugged and
simple.
6. 2.1.0 Gate Valve – Flexible Wedge
A one-piece disc with
a cut or groove
around the edge to
compensate for
irregular sealing
edges.
8. 2.1.0 Gate Valve – Double (Parallel) Disc
Prevents valve
binding due to
thermal
transients.
9. 2.1.1 Valve Stem
• Connects the hand-wheel to the gate.
• Rising stem
– Hand-wheel and stem rising when opening
• Non-rising stem
– Hand-wheel and stem do not rise while opening
• Outside screw-&-yoke (OS&Y)
– Stem rises through the hand-wheel while opening
– Stem does not contact the fluid;
• therefore, the OS&Y is suitable for corrosive fluids
15. 3.0.0 Valves That Regulate Flow
• These valves can not only start and stop flow,
they can regulate flow.
• The disc can be totally removed from the flow.
• The most common types are:
– Globe Valve
– Butterfly Valve
– Diaphragm Valve
16. 3.1.0 Globe Valve
• Valve movement is perpendicular to the
seat.
• Basic types:
– Angle
– Y-type
– Needle
17. 3.1.0 Angle Valve
• A globe valve that changes the
direction of flow.
• Usually, the ports are at 90-degrees to
each other.
• These are commonly used to replace
valve and elbow combinations.
18. 3.1.0 Y-Type Valve
• Has the straight-through flow of a gate valve.
• Has the throttling and flow control of a globe.
19. 3.1.0 Needle Valve
• Commonly used for precise flow control of
instrumentation applications.
• Not commonly available over 1” in size.
20. 3.2.0 Butterfly Valve
• Has a round disc that turns 90 degrees to
mate with the seat.
• Used in low-to-medium pressures and flows.
24. 3.3.0 Diaphragm Valve
• Sealing disc is flexible and seals against the body.
• Suitable for slurries, highly corrosive materials,
and materials that cannot be contaminated.
25. 3.4.0 Needle Valve
• Has a tapered needle instead of a disc to allow
for fine adjustment to the flow.
26. 4.0.0 Valves That Relieve Pressure
• Used to control pressure, not flow.
• Two basic types are:
– Safety Valve
– Pressure Relief Valve
27. 4.1.0 Safety Valve
• Used in pipelines and tanks to prevent
ruptures due to excess pressure.
Water
Hydraulic (Sectional View)
Pneumatic
28. 4.2.0 Pressure Relief Valve
• In-line valve to control a specified pressure in the
liquid circuit.
• These usually have the pressure set at the factory.
29. 5.0.0 Valves That Regulate Direction of Flow
• These valves prevent backflow and are
referred to as “check valves”.
• Common types are:
– Swing
– Lift
– Ball
– Butterfly
– Foot
34. 5.5.0 Foot Valve
• Used at the bottom of a suction line to
maintain the prime of the pump.
35. 6.0.0 Valve Actuators
• Two primary purposes of valve actuators:
– Provide automatic operation of the valve,
– Reduce the effort required to manually operate the
valve.
• Four basic types of actuators:
– Gear
– Chain
– Pneumatic or Hydraulic
– Motor Driven, Electric or Pneumatic.
36. 6.1.0 Gear Actuators
• Reduces the effort required to manually operate the
valve.
• Three basic types:
• Spur Gear,
• Bevel Gear,
• Worm Gear.
37. 6.1.1 Spur Gear Actuator
• Valve stem and driver shaft are parallel.
38. 6.1.2 Bevel Gear Actuator
• Valve stem and driver shaft are 90 degrees to
each other and the gears are cone-shaped.
39. 6.1.3 Worm Gear Actuator
• Valve stem and driver shaft are 90 degrees to
each other. The driver gear (worm) looks like a
screw.
• Used primarily with butterfly valves.
40. 6.2.0 Chain Actuators
• Reduces the effort required to manually operate the
valve.
• Applicable where the valve is not easily accessible;
such as, too high to reach.
41. 6.3.0 Pneumatic and Hydraulic Actuators
• Uses fluid or air pressure to actuate the valve.
• Most of these are spring-loaded to ensure that
the valve fails in a fail-safe position.
42. 6.4.0 Electric- or Air-Motor Driven Actuators
• Uses motors to actuate the valve.
• Motor can be either electrical or pneumatic.
43. 6.5.0 Control Valves
• Variations of the angle, globe, or ball valves that
are controlled by pneumatic, electronic, or
hydraulic actuators.
• Most commonly used for pressure or
temperature control.
44. 7.0.0 Storing and Handling Valves
• Regardless of the size of the valve, the internal
seats, valves, and springs are precision
machined and must be handled carefully to
avoid damage.
45. 7.1.0 Safety Considerations
• When handling and/or working around valves:
– Be aware of all pinch points,
– Do not stand under a load,
– Be aware of surroundings,
– Never operate a valve in a live system without
authorization,
– Use a spud wrench, not your finger, to align flange
bolt holes.
– Never stand in front of a safety relief valve
discharge.
46. 7.2.0 Storing Valves
• Label all valves.
• Never store valves on the ground.
• Cover all open ends with ‘end protectors’.
47. 7.3.0 Rigging Valves
• Protect all threads and ends.
• Use the proper rigging equipment.
• Connect rigging to body only, not the stem,
handle, or through openings.
• Use a tag line, especially for larger valves.
48. 8.0.0 Installing Valves
• Best working height for manual actuator is
between 2’0” and 4’6” from floor.
• Follow schematics exactly.
– Direction of flow.
– Stem position.
• (vertical up works best, horizontal is acceptable, never
position stem vertical down.)
49. 9.0.0 Valve Selection, Types, and Applications
• Valves can be used in many different
applications.
• Valve selection is important; therefore, follow
design requirements exactly at installation.
51. 10.0.0 Valve Markings and Nameplate Information
• Manufacturers Standardization Society (MSS):
– Developed standards for valve markings.
• American National Standards Institute (ANSI):
• American Society for Testing Materials International (ASTM):
– Both have adopted the MSS marking system.
52. 10.0.0 Valve Markings and Nameplate Information
• Bridgewall markings (globe valves):
– Indicates how the valve seat is angled in relation to the
inlet and outlet ports.
• Flow direction arrow:
– Proper direction of fluid flow.
54. 10.2.0 Trim Identification
• Identifies the material of the seat, disc, stem,
and other internal parts if they are different
from the body of the valve.
55. 10.3.0 Size Designation
• Indicates the numerical identification
associated with the pipe size of the
connecting ends.
56. 10.4.0 Thread Markings
• Identifies the size and type of threads for
valves that have threaded connections.
