Trunnion Ball Valve API 608
Key Specifications / Features
The trunnion ball valve can block both upstream and downstream media. And when the pressure in the middle cavity is greater than the seat spring force, the seat will be pushed open to release the pressure inside the chamber to ensure safety. The trunnion ball valves are usually used longer and easier to operate.
Name: Trunnion Ball Valve API 608
Design: API 608, API 6D
Type: Trunnion Mounted Ball Valves
Feature: Fire Safe Design, On-off
Structure: 2 Piece or 3 Piece Body
Bore: Full Bore
Size: 12 Inch
Rating: Class 150
Body: A216 WCB
About API 608
API 608 covers “Metal Ball Valves - Flanged, Threaded and Welding Ends"
API 608 covers up to class 600 flanged, and class 800 thread and weld end.
API 608 requires conformance with ASME B16.34.
API 608 has requirement for strength of ball to stem connection and location of weakest part of stem.
API 608 requires adjustable packing glands
For potential pressure increase from liquid trapped between the seats, 608 refers to ASME B16.34.
API 608 defines allowable distruptions on the flange gasket face.
API 608 tests the valve per API-598, which suggests only low pressure tests recognizing the limitations of soft-seated floating ball valves.