Trunnion Ball Valves – Erreesse Srl Valves
Trunnion valves have mechanical anchoring of the ball at the top and the bottom to avoid axial displacements in the flow direction. During normal operation pressure compresses the seat onto the ball to achieve valve sealing, such construction also ensures automatic cavity relief in case of overpressure in body cavity. As isolation valves, they intercept the flow by opening and closing the port and are mainly recommended on tight shut-off gas and liquid services; trunnion control valves with cage trim are engineered for those services where continuous pressure and flow rate regulation are required.
Erreesse trunnion ball valves are suitable for a wide range of applications and pressures up to 2500 bar and temperatures down to -196°C (-320,8°F) or up to 850°C (1562°F), with sizes range from ½” to 72” with double block and bleed design, metal and soft seated with SIL-3 capability safety rating, engineered for cleaning tools usage with fast and reliable operation. Most designs are double seated but special single seated and X-TRIM solutions for severe and critical services can be also supplied for rising stem (RSBV) or eccentric ball valves providing many features and options beneficial for oil, gas and liquid applications.
There are three main body constructions: side entry, top entry and multiple way. The main difference is based on how the pieces of the valve are manufactured and assembled, from the side or from the top, operation is the same in each case: operating positions for 2-way valves can be either closed (no flow goes through) or open (fully or partially). Multiple way valves (3-way, 4-way or more) have different combinations of flow to serve many different functions: mixing, diverting or isolating and simultaneously bypassing.