Ball Valves

For sizes up to 4"–6" at Class 150–300 in clean, non-abrasive service, a floating ball valve is typically the more economical choice - the ball floats against the downstream seat, providing effective sealing. For 6" and larger, or any size at Class 300 and above, choose a trunnion mounted ball valve: the ball is mechanically anchored, so seat loads remain manageable regardless of line pressure, and operating torque is lower - enabling smaller, less expensive actuators. For frequent automated cycling or DBB (Double Block & Bleed) requirements, always specify trunnion.

A DBB ball valve has two independent seating surfaces (upstream and downstream) each capable of providing a positive seal against line pressure, with a bleed port in the body cavity between them. When both seats are sealed and the bleed valve is open, any pressure in the cavity can be detected or vented - confirming that both seats are holding. DBB ball valves are required by API 6D for metering skids, chemical injection systems, and any application where positive isolation must be verified without removing the valve from the line.

Yes. Our fire-safe ball valves feature secondary metal seats (Stellite or SS316 hard-faced) and graphite body and stem seals that retain sealing function after the primary soft seats (PTFE/PEEK) are destroyed by fire. API 607 applies to 2" and smaller valves; API 6FA applies to larger pipeline valves to API 6D. All fire-safe valves are supplied with a fire-test certificate referencing the applicable standard.

Our trunnion mounted ball valves are available up to ANSI Class 2500 (PN 420 - approximately 420 bar cold working pressure). Floating ball valves are available up to Class 1500 in standard production; Class 2500 is available as a special order. For subsea or ultra-high-pressure service above Class 2500, contact our engineering team for bespoke designs.

Standard full-bore and reduced-bore ball valves are on-off isolation valves - they should not be used for throttling. Partial opening creates a restricted crescent flow area that erodes the ball and seats rapidly, and causes acoustic noise in gas service. If throttling is required, specify a V-port ball valve (characterized V-notch provides a linear or equal-percentage characteristic), a globe valve, or a control valve. V-port ball valves are available from Vajra for modulating duties.