Swing check valve construction

Claim 1

A swing check valve for a large diameter oil and gas transmission pipeline comprising; a generally spherical valve body fabricated from rolled steel; outer generally cylindrical hub members integral with said body and formed therefrom with flow passages therethrough, the inner diameters of said outer hub members reducing gradually to the inner diameter of the pipeline at their outer ends; a separate cylindrical seat hub member of said inner pipeline diameter welded in said body to extend inward thereof around one of said flow passages and generally axially aligned therewith; a seat ring recess cut in the inner end of said seat hub member; a valve clapper; a seal ring positioned by said seat hub member for engagement by said clapper in the closed position; a fixed hinge member having a rotary bearing therethrough mounted on the top portion of said seat hub member without valve body engagement; an arm secured at one end to the back of said valve clapper and having a transverse bore through the other end coaxial with said bearing; a shaft rotatable in said bearing and secured in said bore; and internal access means; whereby the clapper may be mounted and adjusted for proper seating with the seat hub member prior to installation of the seat hub member within the valve body.