Patent ID: 8220478

Claim:
Fluid flow control apparatus comprising a plurality of stacked valves with one or more intermediate flow-directing plates, the valves comprising a main valve having a housing defining an inlet and an outlet for connection into a fluid flowline and a pilot inlet for receipt of a pilot control fluid from a pilot control fluid flowline, the main valve being operable to open or close the fluid flowline in response to the pilot control fluid pressure, and at least one pilot-operated logic control valve having a housing for connection into the pilot control fluid flowline, the stack of valves defining a pilot feed passage of the pilot control fluid flowline for receipt of incoming pilot control fluid, and a pilot return passage of the pilot control fluid flowline that is selectively closable by operation of the logic control valve, the logic control valve being connected to the housing of the main control valve via a first intermediate flow-directing plate, the plate being perforated by a first aperture that interconnects the pilot return passage of the logic control valve and the pilot inlet of the main valve.