Ball, butterfly and cryogenic valve ranges
Valve ranges · 8 pages
Each range page answers one buying question: what the design is, how it compares with the alternative, which ASTM grades and pressure classes apply, and which standards govern testing and documents. A range page stays a draft until its factory document pack is signed off, so values that are not verified yet are marked “To be confirmed”.
Ball valves
- Ball valves · API 6D
Trunnion mounted ball valves
A trunnion mounted ball valve holds the ball on a fixed shaft at the top and bottom, so line pressure is carried by the trunnions instead of the downstream seat. Spring-loaded seats seal against the ball. The design keeps operating torque lower on large bores and high pressure classes, which is why pipeline specifications usually call for it.
Selection, specification and P&T rating - Ball valves · Duplex stainless
Duplex 2205 and super duplex 2507 ball valves
Duplex 2205 and super duplex 2507 ball valves are used where chlorides cause pitting in 316 stainless steel, such as seawater and offshore service. 2507 has more chromium, molybdenum and nitrogen than 2205, which gives it a higher pitting resistance number (PREN). Forged bodies use ASTM A182 F51 or F53; cast bodies use A995 4A or 5A.
Selection, specification and P&T rating - Ball valves · API 6D
Top entry ball valves
A top entry ball valve has a one-piece body with a bolted bonnet on top, so the ball, seats and stem can be removed for repair without cutting the valve out of the line. The design suits welded pipelines and large sizes where in-line maintenance access matters.
Selection, specification and P&T rating - Ball valves · API 6D
Fully welded ball valves
A fully welded ball valve has a sealed steel body with no bolted body joint, made by welding the body parts together. With no body gasket there is no leak path at the joint, which is why the type is used in buried, district heating and offshore lines.
Selection, specification and P&T rating - Ball valves · API 6D
Double block and bleed ball valves
A double block and bleed ball valve isolates a line section with two seating surfaces and a bleed port between them, so the space can be vented and checked at zero pressure. API 6D defines double block and bleed and sets requirements for DBB valves. Pipeline and metering stations use it where a positive isolation check is needed.
Selection, specification and P&T rating - Ball valves · API 6D · API 608
Metal seated ball valves
A metal seated ball valve uses metal-to-metal contact between the ball and the seat instead of a soft polymer insert, so it can seal at high temperature and in abrasive service where PTFE or PEEK would degrade. The trade-off is a higher operating torque and a leakage rate agreed in the purchase order.
Selection, specification and P&T rating