Patent ID: 8066026

Claim:
A diaphragm controlled bypass valve comprising: a first valve housing having an inlet, an outlet and a flow pathway defined between said inlet and said outlet; a needle valve having a needle valve pin disposed at least partially within said flow pathway, said needle valve pin having proximal and distal ends and an angled central portion; a valve seat disposed within said first valve housing configured to receive the angled central portion of said needle valve pin to close said flow path; a second valve housing connected to said first valve housing; a diaphragm extending radially within said second valve housing, said diaphragm and said second valve housing defining a first pressure chamber there between; a second pressure chamber defined between said diaphragm and said first valve housing; a sensing line connected to a bore in said second pressure chamber, said sensing line configured to provide a pressure change to said second pressure chamber to displace said diaphragm within said first pressure chamber; and a shaft assembly coupled to said diaphragm and said needle valve pin such that displacement of said diaphragm moves said shaft assembly to open and close said needle valve; wherein said outlet is a first outlet and said first valve housing further comprising a second outlet; the diaphragm controlled bypass valve further comprising an automatic relief mechanism disposed within said second outlet.