Relia’s standard trunnion ball valves have been developed with incorporating many features according to the highest API 6D standards approved. Complete split boy and fully welded design offers manximum protection against line pressure and thermal distortion with long life and troble free performance.Relia is supplying its products to the crude oil transportation and processing, power engineering, water supply systems and process industries.
1. Seal features
Most types of ball valves(made by China ball valve manufacturer) are produced with spring-loaded seats. This spring load keeps the seat in contact with the ball even in absence of line pressure and makes very effecient seal at low line pressure. As line pressure increases, the seat area creates a piston effect which forces the seat against the ball, therefore a tight seal becomes effective. If the pressure is higher, the force exerted by the seat on the ball is increased by action f the pipeline pressure. Therefore, the higher the line pressure, the greater the piston action. Seats are available in PTFE, R-PTFE, NYLON or others.
2. Self Lubrication
Self lubrication, low friction PTFE is used for stem bearings, stem seals, and body seats. NYLON or other low friction materials are used for seat inserts. Self -lubricating seals and stem bearing give predictable operating torque for the life of the valves.
3. Fire safe construction with secondary metal seat.
Relia’s ball valves (made by China valve manufacturer) have been fire tested and can be supplied to API RP 6F and API 607. The soft seat inserts, irrespective of their materials, will possibly fail when subjected to sudden high temperature conditions. We provide fire-safe design which may substantially prevent leakages through seals when damaged by high temperature. The function of the seats before and after fire test is shown on the scheches. If the seat inserts are destroyed or bumed out, a metal to metal seal is formed between the lower diameter of the seat and ball, while the seat to body seals, the stem packing and the end connections to body seals are designed to resist high temperature and will remain undamaged. Third party certificates on “fire safe” design is available on request.
4. Trunnion Mounting
Trunnion mounted stems absorb the thrust from line pressure, preventing excess friction between the ball and seats, so even at full rated working pressure, operating torque stays low.
5. Body vent and drain
The body cavity may be vented in both open and closed positon.
By Kevin Tsai for Relia Valve – China valve supplier