单项选择题
A.check valve B.non-return valve C.steam trap D.quick closing trap
Fuel oil tanks must be fitted with （） that can be close...
单项选择题Fuel oil tanks must be fitted with （） that can be closed rapidly and remotely in the event of an emergency such as a fire.
A.stop valves B.non-return valves C.quick closing valves D.relief valves
A more sophisticated pressure reducing valve incorporat...
单项选择题A more sophisticated pressure reducing valve incorporates a pilot valve which controls the fluid above the valve operating piston in response to downstream pressureThe bold and italic word “which” means （）.
A.a pressure reducing valve B.a pilot valve C.an operating piston D.downstream pressure
In its simplest form the pressure reducing valve is ope...
单项选择题In its simplest form the pressure reducing valve is opened or closed by （） which is balanced by the downstream pressure acting on a diaphragm.
A.adjusting a nut B.a pre-tensioned spring C.any spring D.upstream pressure
