We are the proud supplier of Perar, Starline, and Pekos trunnion-mounted ball valves. Even down to the body bolts which are 3.1 certified, our valves are Fully Western European. We also keep stocks that comply with many National and International Standards, including NORSOK, National Grid V6, and Lloyds Type Approval. In addition to being approved by many end-user customers.
The valve design incorporates a trunnion at the top and bottom of the ball. This ensures that the ball can only rotate from open to close and vice versa, and not in the direction of the pipe flow. It will also maintain a proper seal on both sides with no requirement for added torque to the stem.
This enables them to be used for larger applications, and/or high-pressure environments. This is due to the unobstructed flow path through the valve and relative ease of operation. They have become an essential component in large piping systems around the world.
What Is A Trunnion Mounted Ball Valve?
A Trunnion Mounted Ball Valve is a quarter-turn valve used to control or isolate the flow of fluids or gases. The ball is supported at the top and bottom rotating between two seats. Differential pressure forces the seat rings against the ball making a seal, whilst, at low or no differential pressure, springs behind the seats ensure sealing. Trunnion-mounted Ball valves are a good solution for larger sizes and higher pressures and also for very low-pressure and fluctuating-pressure applications. Benefits include lower operating torques which are crucial for metal seated valves on high temperature and abrasive applications.
Floating Ball valves differ in that the seats support the ball which is allowed to move or float between the two seats with pressure. A floating Ball is normally used for small sizes and lower pressures. The valve is designed to seal against the downstream seat only as the ball moves from the upstream side.
It’s important to understand that Trunnion Mounted Ball valves are generally more complex than floating ball valves with many more components, it is therefore usually more expensive. In small sizes it’s possible to use either Trunnion Mounted or Floating ball designs, so it is therefore essential to understand the specific performance and sealing characteristics required for the given application when making a selection.
