Check valve

Claim 1

For use in combination with annular flanged ends of two pipes which are clamped together by a plurality of bolts extending along a circular path of greater diameter than the outer diameter of said pipe, a check valve comprising a flat ring having a substantially greater outer diameter than inner diameter and which outer peripheral portion is adapted to be clamped between said pipe ends, a support extending diametrically across the inner diameter of said ring and integrally secured thereto, a detachable clamp, a disc shaped rubber diaphragm sandwiched between said diametrically extending support and said detachable clamp, stiffening segments fastened to substantially semicircular portions of said diaphragm on opposite sides of said support, the outer peripheral portion of said rubber diaphragm being resiliently held in normally seated position on the inner peripheral portion of said ring, whereby fluid pressure flowing through said pipe in an unseating direction will effect pivotal flexing of said diaphragm adjacent and on opposite sides of said support to the open position of said valve and a pair of spacing rings sandwiched between said outer peripheral portion of said flat ring and said pipe flanged ends and being of sufficient thickness to allow lateral withdrawal of said valve without the necessity of separating said flanged ends, the outer peripheral surfaces of said flat ring and spacing rings contacting and being held coaxially of said pipes by said bolts.