Cast Steel Trunnion Mounted Ball Valve
1. Product overview
Metals Valve provides cast steel trunnion mounted ball valves in a wide variety of cast materials covering carbon steel, alloy steel, and stainless steel. The ball of a trunnion mounted ball valve is fixed or constrained at two pivot points(upper stem and bottom stem). Buy using a bearing at the bottom stem(trunnion), only pivoting movement is allowed within the body cavity. The upstream seat is a floating seat and the process pressure pushes it against the ball’s sealing surface. The seat can also be pre-stressed during assembly, using seats that have a spring action. This design applies continuous pressure against a trunnion-mounted ball after the ball is installed, while the top-works apply a load to the entire closure member. Cast steel trunnion mounted ball valves are often soft seated and can attain a bubble tight sealing.
2. Design features and material selection
Design standards: API 6D, API 608, BS 5351, ISO 14313, ASME B16.34; Fire safe to API 607, BS 5146, ISO 10497; End connection: ASME B16.5, ASME B16.25, ASME B16.11; Face to face: ASME B16.10; Inspection and test: API 598, API 6D, EN 12266-1. The cast steel trunnion mounted ball valve is available in either full port(FB) or reduced port(RB), 2 piece split body, lever/gear or actuator operated.
Cast Steel Trunnion Mounted Ball Valve, 2 Piece Split Body, Side Entry - Table Chart | ||||||
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Class 150 | Class 300 | Class 400 | Class 600 | Class 900 | Class 1500 | Class 2500 |
- Design Features
- Material Selection
Design Features
(1) The stem sealant injection fitting is furnished to prevent leakage from the stem in case of emergency.
(2) T-shaped blow-out proof stem design.
(3) The seat sealant injection fitting is furnished to prevent leakage from the seat.
(4) Bleeding/ venting plug to drain the body cavity to avoid over pressure.
(5) Double sealing O-rings to prevent leakage from stem area.
(6) Gasket & O-ring arrangement to prevent leakage from body joint.
(7) Seat spring to exert force on the seat to ensure a tight sealing even at low line pressure.
(8) Fire safe design: in case soft seating materials are deteriorated after fire, metal to metal sealing is available.