Strahman's Trunnion Mounted, Metal Seated Ball Valves have been designed for severe service applications such as those found in oil and gas, petrochemical, refining, polymer, steam, catalyst, DCU (delayed coking unit) and coal gasification industries. Ranging from PN 10 to PN 630-4500 lb., the special coatings (hardened trim) on the ball and metal seats make them ideal for use in high temperature, high pressure and abrasive environments.
The valves come in one-piece and two-piece designs for ease of use and maintenance. The one-piece design includes bottom entry for simplifying maintenance. This is done by dropping the valve internals without having to first remove the valve from the line. Other features of the metal seated ball valve include:
- Chromium carbide coated metal seating designed to minimize peak effect on edges and increase the lifetime of the ball and seat surfaces.
- Floating seats that allow expansion in temperature and the purge of the body inner seat cavity. Independent seats provide bi-direction lightness in the valve.
- Anti-blow out feature, with the valve stem securely mounted in the valve, whereby, even in case of a packing failure, the integral shoulder in the valve body and the shoulder machined on the stem prevents blow-out of the stem.
- Bidirectional upstream sealing, with two independent, spring-loaded seats that prevents line pressure from by-passing the ball. In low pressure situations, the springs maintain seating thrust. As pressure increases, it pushes the up-stream seat against the ball, increasing sealing force. The bottom vent connection allows purging of the inner seat cavity, making the design double block and bleed.
- Anti-static design prevents any accumulation of electric charges on the ball, therefore preventing unexpected electric discharge.
- Separate ball and stem assures proper centering of the ball between the two seats, preventing any bending or flexing of the stem which prolongs the life of the packing.
- Forged body and trim.
