PVF Reference Library · Technical Reference

Valve Types Explained

What gate, globe, ball, butterfly, check, plug, needle and diaphragm valves do, how to recognize them, and which service each one suits. Pressure-temperature ratings come from the valve standard and the nameplate.

Ref PV-0002ASME B16.34ASME B16.10API 600API 608MSS SP-80

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

A valve starts, stops, throttles, diverts or prevents reverse flow in a piping system. Valve types are grouped by how the closure element moves. Linear-motion valves (gate, globe, diaphragm, needle) use a stem that rises or lowers. Quarter-turn valves (ball, butterfly, plug) open or close in 90°. Check valves work automatically on the flow itself. The type decides whether a valve can throttle, how much pressure drop it causes and how quickly it operates.

How to identify

Handle style: a lever or gear operator usually means a quarter-turn valve. A handwheel usually means a gate, globe or diaphragm valve.
Body shape: a globe valve has a bulbous body with an S-shaped flow path. A gate valve has a tall bonnet and a straight-through path. A butterfly valve is a thin wafer or lug body between flanges.
Flow arrow: globe and check valves are directional and are marked with an arrow.
Markings: the body or nameplate shows the size, pressure class or CWP rating, body material and trim. Read these before you quote a replacement.

Valve types at a glance

Type	Motion	Throttling?	Typical service	Notes
Gate	Linear, multi-turn	No; on/off only	Isolation in water, oil, gas, steam	Low pressure drop when fully open; throttling damages the seats
Globe	Linear, multi-turn	Yes	Flow control, bypasses, steam	Higher pressure drop; install with the flow arrow
Ball	Quarter-turn	Limited (V-port types are made for it)	Tight shutoff, general service	Full-port vs standard-port changes the bore
Butterfly	Quarter-turn	Yes, within limits	Large-diameter water, HVAC, process	Wafer vs lug body; check seat material
Plug	Quarter-turn	Some designs	Gas, slurries, multi-port diverting	Lubricated and non-lubricated designs
Check	Automatic	No	Prevents backflow	Swing, lift, spring and wafer types; orientation limits apply
Needle	Linear, fine	Yes, fine control	Instruments, gauges, sampling	Small flow capacity
Diaphragm	Linear	Yes	Corrosive, sanitary, slurry	Diaphragm material limits temperature and chemicals

Key points

Match end connections (threaded, socket weld, flanged, grooved, press, solder) as well as size and type. Face-to-face dimensions for flanged valves are standardized in ASME B16.10.
Pressure rating depends on the body material, temperature and class. Get it from ASME B16.34, the product standard (such as API 600, API 608 or MSS SP-80) or the nameplate, not from the valve type.
Seat and seal materials (PTFE, EPDM, metal) often limit temperature and fluid compatibility more than the body does.

Common mistakes

Using a gate valve to throttle flow.
Installing a swing check vertically with the flow downward. Many swing checks are not designed for that orientation.
Replacing a full-port ball valve with a standard-port valve where pigging, flow capacity or drainage matters.

Governing standards: ASME B16.34 (valves: flanged, threaded and welding end); ASME B16.10 (face-to-face dimensions); API 600, API 602, API 608, API 609, API 594; MSS SP-80, SP-67, SP-71, SP-110.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

More in Technical Reference

← All PVF sheets