Gate, globe, ball, butterfly, check, plug, needle and forged valves in carbon steel, stainless steel,
alloy steel, duplex and nickel alloys — with the body materials, trim, pressure classes and testing
you need to specify them.
Product Overview
Valves That Match the Line They Serve
We supply gate, globe, ball, butterfly, check, plug and needle valves, and compact
forged steel valves for small-bore lines — in carbon steel, stainless steel, alloy steel, duplex and
nickel alloys, for isolation, flow control and non-return duty.
Valves are supplied with body and trim materials, end connections and pressure class matched to your
piping specification, with the pipe, fittings, flanges and bolting to go with them. Every valve is
pressure tested and supplied with its material and test certificates. When your project needs
independent verification, inspection by your nominated agency is carried out before dispatch.
Every valve does one of three jobs: isolate the line, regulate the flow, or stop it running backwards. The type decides which job it does well.
IsolationLinear
Gate Valve
A wedge lifts clear of the bore, leaving a straight, full-bore path with very little pressure drop. For fully open or fully closed service.
Standards
API 600 · API 603 · ISO 10434
Classes
150 – 2500
RegulationLinear
Globe Valve
A plug moves onto a seat as the flow turns through the body. Controls flow precisely and shuts off tightly, at the cost of more pressure drop.
Standards
BS 1873 · ASME B16.34 · ISO 15761
Classes
150 – 2500
IsolationQuarter-turn
Ball Valve
A ball with a bore through it turns 90° to open or close. Quick to operate with tight shut-off. Floating ball in small sizes, trunnion mounted in large sizes and high classes.
Standards
API 608 · API 6D · ISO 17292
Classes
150 – 2500
IsolationRegulationQuarter-turn
Butterfly Valve
A disc on a shaft turns across the flow. Short, light and economical in large sizes. Concentric for utilities; double and triple offset for tight shut-off at higher pressure and temperature.
Standards
API 609 · EN 593
Body
Wafer · lug · double flanged
Non-returnAutomatic
Swing Check Valve
A hinged disc is pushed open by forward flow and swings shut if the flow reverses. Low pressure drop; best in horizontal lines.
Standards
BS 1868 · API 594 · ASME B16.34
Classes
150 – 2500
Non-returnAutomatic
Dual Plate Check Valve
Two spring-loaded half discs fold open with the flow and snap shut before it reverses. Compact, light and quick to close, limiting water hammer.
Standards
API 594 · API 6D
Body
Wafer · lug · flanged
IsolationQuarter-turn
Plug Valve
A tapered or cylindrical plug with a port turns 90°. Simple and robust, with few cavities, for slurries, gas and multi-port diverting service.
Standards
API 599 · API 6D
Type
Lubricated · sleeved · lined
RegulationLinear
Needle Valve
A fine tapered needle gives very precise control of small flows. Used on instrument, gauge, sampling and hydraulic lines.
Standards
MSS SP-99
Ends
NPT · compression · socket weld
Small boreGate · Globe · Check
Forged Steel Valve
Compact gate, globe and check valves with forged bodies, for high-pressure small-bore lines, drains, vents and instrument take-offs.
Standards
API 602 · ISO 15761
Classes
800 · 1500
How They Work
Five Ways to Close a Pipe
Each drawing shows the valve closed, with the closing element in amber and a grey arrow for how it moves. How it closes decides the pressure drop, the speed and how well it controls flow.
Gate
Linear · on / off
The wedge slides down across the bore. Fully open, nothing is left in the flow path.
Globe
Linear · throttling
The plug lifts off a seat inside the body. The flow turns through an S-shaped path, which makes fine control possible.
Ball
Quarter-turn · on / off
The ball turns 90°. Open, its bore lines up with the pipe; closed, the solid side faces the flow.
Butterfly
Quarter-turn · on / off & throttling
The disc turns on its shaft across the bore. Open, it stays edge-on in the flow.
Check
Automatic · non-return
Forward flow swings the disc open; if the flow reverses, the disc falls back onto the seat.
Standards & Classes
Which Standard Each Valve Is Built To
Each valve type has its own design standard. The pressure–temperature rating of the body comes from ASME B16.34, which works like the flange ratings in ASME B16.5.
Valve
Design standard
Scope
Gate, cast steel, bolted bonnet
API 600 · ISO 10434
Flanged and butt weld gate valves for refinery and process service, Class 150 to 2500.
Gate, corrosion-resistant
API 603
Lighter-wall stainless and alloy gate valves, Class 150, 300 and 600.
Gate, globe & check, forged
API 602 · ISO 15761
Compact forged steel valves for small bore, typically NPS 2 and smaller, Class 800 and 1500.
Globe, steel
BS 1873 · ASME B16.34
Bolted bonnet globe and stop-check valves for the petroleum and process industries.
Check, steel
BS 1868 · API 594
Swing check (BS 1868) and wafer, lug and flanged check valves including dual plate (API 594).
Ball, metal body
API 608 · ISO 17292
Floating and trunnion ball valves for process piping.
Pipeline valves
API 6D
Ball, gate, plug and check valves for oil and gas pipelines, Class 150 to 2500.
Butterfly
API 609 · EN 593
Concentric (Category A) and double and triple offset (Category B) butterfly valves.
Plug
API 599
Metal plug valves, flanged, threaded and welding end.
All steel valves
ASME B16.34 · B16.10
Pressure–temperature ratings, wall thickness and face-to-face dimensions.
Swipe the table sideways to see every column
Pressure classes work as they do for flanges: the class is a designation, and the pressure allowed depends on the body material and the temperature. See the pressure ratings on the Flanges page. Class 800 is an extra intermediate class used for small forged valves.
Body Materials
Cast Bodies, Forged Bodies and Their Equivalents
Larger valves have cast bodies; small-bore valves are forged. Each cast grade has a forged equivalent, so valves of both kinds can be matched to the same piping class.
Material
Cast body
Forged body
Where it is used
Carbon steel
Carbon steel
A216 WCB · WCC
A105
General process, oil, gas, water and steam service.
Low-temperature carbon steel
A352 LCB · LCC
A350 LF2
Impact tested for cold service, to about −46 °C.
Stainless steel
304 / 304L
A351 CF8 · CF3
A182 F304 · F304L
Water, food and mildly corrosive service.
316 / 316L
A351 CF8M · CF3M
A182 F316 · F316L
Chemical, pharmaceutical, coastal and cryogenic service.
347
A351 CF8C
A182 F347
High-temperature stabilised service.
Alloy steel
1¼Cr – ½Mo
A217 WC6
A182 F11
Steam and high-temperature process lines.
2¼Cr – 1Mo
A217 WC9
A182 F22
High-pressure steam and hydrogen service.
5Cr – ½Mo
A217 C5
A182 F5
Refinery service with hot sulphur-bearing streams.
9Cr – 1Mo – V
A217 C12A
A182 F91
Main steam in power plants.
Duplex & super duplex
Duplex 2205
A995 4A
A182 F51
Seawater, offshore and chemical service.
Super duplex 2507
A995 5A
A182 F53
Seawater and high-chloride service.
Super duplex S32760
A995 6A
A182 F55
Seawater, firewater and sour service.
Nickel alloys & bronze
Monel 400
A494 M35-1
B564 N04400
Seawater and hydrofluoric acid.
Inconel 625
A494 CW-6MC
B564 N06625
Seawater and severe chemical service.
Hastelloy C276
A494 CW-12MW
B564 N10276
Wet chlorine and mixed acids.
Nickel aluminium bronze
B148 C95800
–
Seawater butterfly and check valves.
Swipe the table sideways to see every column
The body material sets the pressure–temperature rating and must suit the fluid. Chemistry and strength of the forged grades are on the Flanges page.
Trim
The Parts That Do the Sealing
The trim is the stem, the closing element and the seat faces — the wetted parts that wear. For gate, globe and check valves it is specified by an API 600 trim number.
Trim number
Stem · disc · seat
Typical service
Trim 1
13Cr · 13Cr · 13Cr
General oil, gas and steam service at moderate temperature.
Trim 5
13Cr · hard-faced · hard-faced
Erosive, high-pressure and high-temperature service.
Trim 8
13Cr · 13Cr · hard-faced
The most common general-purpose refinery and steam trim.
Trim 9
Monel · Monel · Monel
Seawater, brine and hydrofluoric acid.
Trim 10
316 · 316 · 316
Corrosive service where 13Cr would be attacked.
Trim 12
316 · 316 · hard-faced
Corrosive service with erosion or wear.
Swipe the table sideways to see every column
13Cr is 13 % chromium martensitic stainless steel (type 410). Hard-facing is a cobalt-chromium or nickel-chromium alloy welded onto the seat faces.
Soft seats
PTFE, reinforced PTFE, PEEK or nylon seats in ball and butterfly valves, for bubble-tight shut-off at moderate temperature.
Metal seats
Hard-faced or tungsten-carbide coated seats, for high temperature, abrasive media and fire-safe service.
Packing & gaskets
Graphite stem packing and spiral wound or graphite bonnet gaskets, with low-emission packing on request.
Ends & Operation
How the Valve Connects and How It Is Operated
End connections match the piping, bonnets match the pressure and temperature, and the operator matches the size and how often the valve is used.
End connections
Flanged
Raised face or ring type joint, drilled to ASME B16.5 or EN 1092-1. The most common end for process valves.
Butt weld & socket weld
Butt weld ends bevelled to ASME B16.25; socket weld ends to ASME B16.11 for forged valves.
Threaded, wafer & lug
NPT or BSP threaded for small bore; wafer and lug bodies for butterfly and dual plate check valves.
Bonnets & operators
Bonnets
Bolted bonnet as standard; pressure-seal bonnet for high classes; welded bonnet on forged valves; extended bonnet for cryogenic service.
Manual operation
Handwheel for gate and globe valves, lever for small ball and butterfly valves, gearbox for large sizes.
Actuated
Pneumatic or electric actuators for remote and automatic operation, with limit switches and positioners.
Pressure Testing
Every Valve Tested Before It Ships
Valves are pressure tested to API 598: the shell for strength, and the seat for shut-off. Test pressures follow the valve's rating; these are for carbon steel bodies, Material Group 1.1.
Shell test pressure by class
bar · hydrostatic, carbon steel body
Class 2500639
Class 1500383
Class 900230
Class 600154
Class 30077
Class 15030
The shell test is 1.5 times the rated pressure at 38 °C, rounded up. It proves the body, bonnet and joints before the valve leaves.
Tests to API 598
What each test checks
Shell testWater at 1.5 × rating, valve part-open. No visible leakage through the body.
Backseat testFor gate and globe valves, the stem backseat is tested so the packing can be changed under pressure.
High-pressure closure testWater at 1.1 × rating against the closed seat, within the allowed leakage.
Low-pressure closure testAir or gas at 4 to 7 bar against the closed seat. Soft-seated valves must show no leakage.
Class
Rating at 38 °C bar
Shell test bar
Seat test, water bar
Seat test, air bar
150
19.6
30
22
4 – 7
300
51.1
77
57
4 – 7
600
102.1
154
113
4 – 7
900
153.2
230
169
4 – 7
1500
255.3
383
281
4 – 7
2500
425.5
639
469
4 – 7
Swipe the table sideways to see every column
API 598 Pressure TestShell, backseat and seat tests
Fire SafeDesign certified to API 607 / API 6FA
Fugitive EmissionLow-emission stem sealing, ISO 15848
PMI TestingConfirms body and trim alloys
Casting NDTRadiography, MPI or dye penetrant
CertificatesMTC EN 10204 3.1 / 3.2 and test report
Selection
Which Valve for Which Duty?
A starting point for choosing the valve type. Tell us the fluid, pressure, temperature and duty, and we will quote the valves that fit.
Duty
Typical choice
Why
Isolation, full bore, low pressure drop
Gate · full-bore ball
Nothing left in the flow path when open.
Quick on/off with tight shut-off
Ball valve
A quarter turn, with soft seats that seal bubble-tight.
Throttling and flow control
Globe · needle
Flow changes steadily with stem travel.
Large water and cooling lines
Butterfly, concentric
Light, short and economical in large sizes.
High temperature, tight shut-off
Triple offset butterfly · gate
Metal seats that seal without rubbing.
Stop reverse flow, horizontal lines
Swing check
Low pressure drop through the open disc.
Stop reverse flow, compact or pump discharge
Dual plate check
Short, light and fast closing against water hammer.
Small-bore high-pressure lines
Forged valves, API 602
Compact bodies for drains, vents and instrument take-offs.
Slurries and multi-port diverting
Plug valve
Few cavities for solids to collect in.
Oil and gas pipelines
API 6D ball · gate · check
Built and tested for pipeline service.
Steam
Gate · globe, Trim 8, WCB or WC6
Hard-faced seats resist wire drawing and erosion.
Seawater
Duplex · NAB · Monel trim
Resist chloride pitting and erosion.
Swipe the table sideways to see every column
This guide is for orientation only. The choice of valve, materials and pressure class depends on the full service conditions and the governing piping code, and remains the responsibility of the design engineer.
Questions Buyers Ask
Valves, Explained
What is the difference between a gate valve and a globe valve?
A gate valve lifts a wedge clear of the flow path, so when fully open it gives a straight, full bore with very little pressure drop. It is for on/off isolation and should not be used part-open. A globe valve lowers a plug onto a seat, with the flow turning through the body. It has a higher pressure drop but controls flow well, so it is used for throttling and regulation. See how they work.
Should I choose a ball valve or a butterfly valve?
Both open and close with a quarter turn. A ball valve gives a tight shut-off and a full or nearly full bore, and suits most sizes up to the medium range. A butterfly valve is lighter, shorter and cheaper in large sizes, so it is preferred for large water, cooling and utility lines. High-performance double and triple offset butterfly valves are used for tighter shut-off and higher pressures and temperatures.
What does a valve trim number such as Trim 8 mean?
API 600 numbers the combinations of materials used for the stem, the disc or wedge and the seat surfaces. For example, Trim 1 is 13 % chromium stainless throughout, Trim 5 has hard-faced seats and wedge, Trim 8 has a 13 % chromium stem and wedge with hard-faced seats, and Trim 10 is type 316 stainless steel. See the trim table.
What is a Class 800 valve?
Class 800 is an intermediate pressure class, between Class 600 and Class 900, used for small forged steel gate, globe and check valves to API 602, typically NPS 2 and smaller with socket weld or threaded ends.
How are valves tested before dispatch?
Valves are pressure tested to API 598. The shell test checks the body at about 1.5 times the rated pressure at 38 °C. The seat or closure tests check shut-off, with water at about 1.1 times the rated pressure and with air or gas at low pressure. Gate and globe valves also get a backseat test. Leakage must be within the limits of the standard. See pressure testing.
What documents are supplied with valves?
Valves are supplied with the material test certificates for the pressure-containing parts, to EN 10204 Type 3.1 or 3.2, and the pressure test certificate to API 598. Fire-safe, fugitive-emission or NACE certificates are supplied when the order calls for them, along with the agency's inspection release note when third-party inspection is required. More on our quality & inspection page.
Complete the Line
Everything That Goes With the Valve
Pipe, fittings, flanges and bolting in matching grades, so the whole line comes from one supplier with one set of documents.
Send the valve type, size, class, ends and materials. We will confirm availability and quote, with material and test certificates and the inspection you need.
