Summary of Valve Types

Control Valves
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Summary of Valve Types covers globe valve, needle valve, ball valve, gate valve, plug valve, check valve, butterfly valve, non-return valve, pressure relief valve.

Summary of Valve Types

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Globe valve

• Suitable for regulating flow
• Tight shut-off
• Pressure drop when open
• Used for high pressure clean fluids

Needle valve

• Suitable for regulating flow
• Fine control in small diameter piping
• Tight shut-off
• Used for clean fluids that have low flows
• High pressure drop when open

Ball valve

• Not suitable for regulating flow except in some specialized ball valves
• Tight shut-off
• Low pressure drop when open
• Used for gas, liquids or slurries

Butterfly valve

• Suitable for regulating flow
• Not suitable for tight shut-off
• Low pressure drop when open
• Used for low line pressure and large pipe line diameters
• Wide range of service: gas, liquids and slurries

Gate valve

• Not suitable for flow regulation, only suitable for on or off
• Tight shut-off
• Low pressure drop when open

Diaphragm valve

• Suitable for on/off or narrow range throttling control
• Tight shut-off
• Low pressure drop when open
• Used for corrosive fluids and slurries

Plug valve

• Suitable for regulating flow
• Tight shut-off
• Quick opening
• High pressure drop when open

Non-return valve

• Allow flow in one direction only
• Self closing
• Low pressure drop when open
• Not suitable for reciprocating pump discharge

Pressure relief valve

• Opens at pre-determined pressure level

4 Likes
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Valves regulate fluid flow and isolate equipment. They are normally flanged to allow easy replacement and insertion of blanks or caps. However, valves can also be welded into a piping system.

The location of valves can be found by studying piping and instrument diagrams (P&IDs) and the physical placement by on-site review. Valve types include:

Ball Valves

Operate by aligning an orifice in a sphere with a pipe to allow fluid flow; rotating the sphere 90 degrees blocks the flow. Ball valves are used as on/off devices as they are not suited to regulate flow.

Gate Valves

Operate by raising or lowering a vertical valve disk or gate in the path of fluid flow.

Isolation Valves

Separate pumps, compressors and other equipment from the pipelines; generally a manual gate valve.

Block Valves

Separate one item of equipment from another and seals against liquid flow.

Emergency Block Valves (EBV)

Separate one item of equipment from another during fire or other emergencies. These are usually arranged as fail safe emergency block valves (FSEBV).

Zone Valves

Isolate units; generally located at the end of pipe racks and at ground level. Also known as battery limit valves.

Fail-Safe Valves

Fail in a fully opened or fully closed position upon loss of power. The correct fail-safe position must be determined by process hazard evaluation. There are two types:

Air Operated Valves

Use air as the control medium to operate the valve; at air failure, the valve fails to the safe position. They may have compressed air or nitrogen tanks to power the valves to the safe position.

Motor Operated Valves

Use electric power; upon power failure, they fail to the safe position. They may have batteries to power the valves to the safe position.

Emergency Shutdown (ESD) Valves

Ball valves that close within 1 to 1.5 sec per in. of valve diameter; and seals in both the up and down stream directions. Same as block or zone valves, except that they fail closed, seal the equipment, operate under elevated temperature and are interlocked to the critical alarms associated with that unit.

Flange-less Valves

Standard valves without flanges. Held in place by rods or long bolts placed between the pipe flanges.

Fire Rated Valves

Listed by a nationally recognized testing laboratory as being capable of retaining liquid or gas without leaking even though subjected to a hydrocarbon exposure fire.

Check Valves

Allow fluid flow in only one direction.

Excess Flow Valves

Close automatically if fluid flow rates exceed a critical value. The critical flow rate of excess flow valves depend upon the physical characteristics of the fluids as well as flow rates.

Safety Relief Valves

Open automatically if pressures exceed set values.

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The pinch valve
Resistant to abrasion, is used in industrial applications where fluids contain solid particles, offering high sealing performance, long service life, and minimal maintenance requirements.