Fluid flow valve with variable flow rate

摘要

An improved fluid flow valve (10) for a fluid flow control system. The flow valve (10) includes a flow-regulating assembly (40) having a housing (44) having a piston bore (15) within which is slideably disposed a piston-like member (42). The piston-like member (42) has a primary flow passage (52) and at least one secondary flow passage (54) formed therein. A first portion (42a) of the piston-like member (42) is configured for mating with a seat (46) of the housing (44), and a resilient member (48) biases the piston-like member (42) away from the seat (46). When at least a predetermined fluid pressure differential exists, the first portion (42a) mates with the seat (46) and causes at least one secondary flow passage (54) to be at least substantially closed such that fluid can substantially flow only through the primary flow passage (52).