Floating and trunnion-mounted ball valves, soft or metal seated, fire-safe and ready for actuation, for oil, gas, water and marine lines. Made in Britain by Young & Cunningham, selected, supplied and supported in the GCC by Petromarsh.
Tap a part to see what it does. The blue line is the line fluid. Open, the hole through the ball lines up with the pipe; a quarter turn closes it.
Lever or gear operator. A lever for small valves; the lever lies along the pipe when open, so the position is clear at a glance. Larger valves use a gearbox, and actuated valves use a pneumatic, hydraulic or electric actuator on an ISO 5211 mounting pad.
Stem. Turns the ball through 90 degrees. On fire-safe and high-pressure valves it is blow-out proof: a shoulder inside the body stops it being pushed out by line pressure.
Stem seals. O-rings, PTFE chevrons or graphite rings around the stem. Graphite is used for fire-safe duty because elastomers and PTFE can burn away in a fire.
Body. The centre section that holds the ball and seats. It can be one-piece, two-piece or three-piece, with side or top entry. The body cavity is where trapped liquid can build pressure, so cavity relief matters.
Ball with bore. A polished sphere with a hole through it. Full bore matches the pipe, reduced bore is one size smaller. In a floating design the line pressure pushes the ball onto the downstream seat.
Seats. Rings that seal against the ball. Soft seats (PTFE, reinforced PTFE, PEEK) give bubble-tight shut-off. Metal seats with hard coatings handle high temperature, solids and erosion.
End caps. On a three-piece valve the end caps carry the pipe connection and bolt to the body. Remove the body bolts and the centre swings out for seat change while the end caps stay welded in the line.
A ball valve controls flow with a sphere that has a hole through it. Turn it a quarter turn so the hole lines up with the pipe and the valve is open. Turn it back and the solid side of the ball blocks the flow against the seats.
One 90 degree turn opens or closes the valve. That makes ball valves quick to operate by hand and simple to actuate, which is why they are used for emergency shutdown (ESD) and on-off automation.
In a floating valve the ball is held only by the seats. Line pressure pushes it onto the downstream seat to seal. Simple and tight, but torque rises with size and pressure.
In a trunnion valve the ball is held by shafts top and bottom, and spring-loaded seats press onto it. Torque stays low on large, high-pressure valves, and each seat can seal on its own.
Ball valves differ in how the ball is held, the bore, the seats, how the body comes apart and what extra safety features they carry. Tap a type to see where it fits.
The ball floats between two seats and line pressure pushes it onto the downstream seat. Simple, compact and tight. Operating torque grows quickly with size and pressure, which limits the range.
The usual design for small and medium valves on GCC process, utility and instrument lines.
Shafts above and below hold the ball, and springs push the seats onto it. Torque stays low, so large high-pressure valves can be operated and actuated. Each seat seals on its own, which allows double block and bleed.
Standard on oil and gas pipelines, manifolds and high-pressure gas plants.
A full bore valve has a hole the same size as the pipe, for low pressure drop and pigging. A reduced bore valve is one size smaller inside, so it is lighter and cheaper where some pressure drop is acceptable.
Full bore is specified on piggable pipelines; reduced bore is common in plant piping.
Soft seats in PTFE, reinforced PTFE, nylon or PEEK give bubble-tight shut-off at moderate temperatures. Metal seats with tungsten carbide or chrome carbide coatings handle high temperature, sand and erosive duty.
Metal seats are used on sandy well fluids, hot service and severe ESD duty.
A side entry valve splits through the body to reach the ball. A top entry valve has a bolted cover on top, so the ball and seats can be removed while the body stays welded in the line.
Top entry is chosen for welded high-pressure lines where cutting out a valve is costly.
A two-piece body has one joint and suits general use. A three-piece body has a centre section between two end caps; after the end caps are welded in, the centre swings out for seat and seal replacement.
Three-piece valves are common on socket-weld utility and chemical lines.
Both seats seal at the same time with the cavity between them vented through a bleed valve. This proves isolation before work starts. Trunnion valves with self-relieving or double-piston seats give this in one body.
Required by many GCC operators for isolating pumps, meters and pig traps.
The body follows the piping class. The ball and seats decide tightness and life. In the Gulf the usual concerns are seawater, sour gas, sand in well fluids and fire-safe duty on hydrocarbons.
| Part | Carbon and low-temp steel | Stainless and duplex | Bronze and special alloys |
|---|---|---|---|
| Body and end caps | Cast or forged carbon steel, low-temp steel for cold gasA216 WCB · A105 · A352 LCC · A350 LF2 | 316 stainless, duplex and super duplexA351 CF8M · A182 F316 · A182 F51 / F55 | Bronze, aluminium bronze, brass and ductile iron for water and marine dutyB62 · B148 C95800 |
| Ball and stem | Carbon steel ball with ENP coating, 17-4PH stemENP · A564 630 | 316 or duplex ball, solidA182 F316 · F51 | Alloy 625 overlay, or tungsten carbide coating for metal seatsASTM B446 · HVOF WC |
| Seats and seals | PTFE, reinforced PTFE, nylon or PEEK soft seats; graphite stem seals for fire-safe; anti-explosive-decompression O-rings for high-pressure gasAPI 607 · ISO 10497 · NORSOK M-710 | ||
Pipeline valves follow API 6D. Plant valves follow API 608 or ISO 17292. Fire-safe testing applies to both when the fluid can burn.
Trunnion and floating ball valves for pipelines, with DBB and DIB definitions and testing.
Metal ball valves for flanged, threaded and welding ends in petroleum and process plants.
Metal ball valves for petroleum, petrochemical and allied industries, including anti-static requirements.
Pressure and temperature ratings, wall thickness and materials.
Fire type test: the valve must still hold pressure and leak only a little after burning.
Shell and seat leak tests for plant valves. API 6D sets its own tests for pipeline valves.
Type testing of stem seals for leakage to air.
Actuator mounting flanges and drives, so any compliant actuator fits.
Material and hardness limits for hydrogen sulphide service.
Your engineers red-line our drawings, you approve the design twice before production starts, and you can witness the tests. Tap a step to see what happens and which documents you receive.
Young & Cunningham has made valves in Britain since the 1920s, with a long history of supplying the UK Ministry of Defence. Their ball valves include floating, trunnion, extended neck and lockable designs, with lever, gear or actuated operation, in stainless and carbon steel, bronze, aluminium bronze and ductile iron. Petromarsh is their exclusive representative in the GCC.
If you have valve datasheets or a line list, send them. If you do not, the items on the right are enough for us to select the valve and reply with a proposal.
