Fast closing check valves are installed in the turbine extraction pipe lines that supply steam to feed water heaters,auxiliary turbines and other equipment. Closing action in less than 1 second. The valves have side mountedactuators and are spring closing
Sempell Fasani Check Valves
ASME 150 to 1500
DN 150 to 1500 (NPS 6 to 60)
carbon steel, low alloy steel,stainless steel
stainless steel 13 % Cr(trim 1 acc to API 600)
flanged or butt weld ends
pneumatic or hydraulicactuator
The disc will freely close as a result of reversed flow.
Complete disc closure at no flow conditionsis assured by an off-set between the seatingsurface and the lever.
The disc is provided with an anti-rotational device to avoid damage due to induced flow instability.
Free swinging disc operation when the actuator is in open position (pressurized�cylinder and compressed spring).
A vertical seat design, a large opening angle of the disc (75�) and an accurate design of the�internal geometry gives a very limited internal turbulence. This results in reduced pressure loss.
During the fast air exhaust the compressed spring allows a closure in less than 1 sec (the complete seat closure will be effective only when the steam flow becomes zero).
The actuator action is limited to the first part of the stroke leaving a free swinging motion of the disc for few degrees when it is near the closed position. This avoids possible deformation by repeated internal shocks by forced closure.
The standard actuator configuration includes: limit switches, pressure gauge and filter, quick exhaust valve and local closure test device.
Quarter turn actuators assures the safety conditions for operators.