Cast Trunnion Ball Valve

Applicable Standards

Basic Design: API 6D, ISO 17292, BS 5351, API 608

Face to Face: ASME B16.10

Flange End: ASME B16.5

Butt Welding End: ASME B16.5

Test and Inspection: API 598

Fire-safe Test: API 607 / API 6FA

Fugitive Emission Test: ISO 15848-2

Pressure & Temp.: ASME B16.34

Sour: NACE MR 0175

Seat To Ball Sealing

Soft seats are standard. Seat inserts of synthetic material such as RTFE, Devlon, or PEEK are contained within a onepiece metal seat ring. With no, or very low line pressure, sealing between the seats and ball is achieved by the seat springs, ensuring dependable performance for cast trunnion ball valve applications.

Self Relieving Seat

This standard feature is designed to prevent excessive pressure buildup within the valve by automatically relieving pressure when body cavity pressure exceeds 133% of pressure rating. Double Piston Seat is also available as an option, enhancing ball valve application flexibility.

Seat To Body Sealing

Two different types of seals are used to isolate the line pressure from the body cavity. Primary sealing is accomplished by an elastometric seal such as Viton or HNBR, and secondary firesafe sealing is accomplished by a graphite seal ring, meeting industrial valve standards for high-pressure applications.

Sealant Injection Fittings

If the seat ring becomes damaged, this feature provides the user with an easy way to inject an emergency sealant to restore a tight seal. It also allows for the sealing surfaces of the ball and seat to be periodically flushed to clear away debris which may impair sealing—an important advantage for cast trunnion ball valve operation in harsh conditions.

Stem Sealing and Sealant Injection Fitting

ASME Class 150 through 2500 utilize two “O” Rings and a graphite seal ring to effect a tight stem to body seal. In case of damage to the soft seals, stem seal integrity can be restored by injecting sealant into the sealant injection fitting.

Double Block and Bleed

KFTE cast trunnion ball valves incorporate an independent positive seal at both the upstream and downstream ends. In the fully closed position, the body cavity is isolated from upstream/downstream pressure. The body cavity may be vented by use of the body bleed plug to confirm the integrity of the seats.