Metal Seated Ball Valves
Metal seat ball valve is selected for the heavy duty medium such as solid particles, abrasive, high temperature or high pressure class or with anyone of the mentioned condition combined, typical pipeline like coal chemical , pulp & paper and crude oil refinery etc.The metal seat ball valve shows good sealing performance, long time service, low torque and comparatively less pressure loss in above mentioned service. The general valve like globe and gate valve couldn’t meet such working condition, so the metal seat ball valve growing up more demands for severe service. ● Trunnion Ball has upper stem and lower trunnion guide reduce stem torque ● Graphite sealing between seat and stem suitable for high temperature ● Piston Inconel X750 spring seat balance the seat pressure ● Double bleed and block system ● Fire safe and anti-blow out stem ● The trunnion mounted metal seat ball valve normally has the structure of seat sealing at the ball inlet end. The two seats an independently cut off the medium at the inlet and outlet ends to achieve double block function. When the ball valve is closed, even if both ends of the inlet and outlet of the valve are pressurized at the same time, the middle cavity of the valve and the passages at both ends can be blocked from each other, and the remaining medium in the middle cavity can be discharged through relief valves.FIG . Trunnion mounted ball valve type
metal seated ball valve seat open and seat close sectional diagram.
QL Metal Seated Ball Valves are mostly used for the severe service conditions like high corrosion and erosion process fluid with solid particles and high temperatures or high pressure, such conditions the soft seated ball valve couldn’t be durable due to seat material difference. Upon enquiry request, the information of valve medium and temperature is quite important for QL sales engineer to choose correct model type.
Seat closed
Seat open