Abstract: A check valve assembly has a body having a central cavity intersected by upstream and downstream flow passages. A seat is secured by a threaded engagement in the upstream flow passage. An access bore intersects the cavity and has a support shoulder formed in it. A holder is supported on the support shoulder. A flapper is pivotally secured to the holder and located in the cavity for movement between an open position and a closed position blocking flow through the seat. A straight edge portion in the access bore engages a straight edge portion of the holder to prevent rotation of the holder. A fastener extends through a hole in the support shoulder into engagement with the seat to prevent rotation of the seat.

Abstract: Pumps and plunger assemblies are provided. An exemplary pump can have or contain a cylinder mounted in a pump housing, a plunger assembly including a crosshead, a plunger, a stationary bushing having substantial portions fixedly mounted within a laterally extending bore of the crosshead, and a non-stationary pivotally rotating wrist pin mounted within the bushing. The pump can also include a power end seal assembly including a seal housing extending at least partially through an aperture in the sealed fluid end-facing side of the power end of the pump, a power end seal disposed therein in sealing contact with the power end section of the plunger and a splashguard assembly.

Abstract: An emergency pressure relief valve has a housing fluidly connected to a pressurized system line carrying a system fluid. The housing carries a piston and a valve member which move within the housing between a closed position and an open position. The piston defines an upper chamber and a lower chamber within the housing. A control fluid is supplied to the upper chamber, and the pressure of the control fluid exerts a biasing force to a first side of the piston. The biasing force holds the valve member and piston in a closed position when the pressure of the system fluid is at an acceptable level. As the pressure of the system fluid rises above the acceptable level, the valve member moves to an open position. While the piston moves from the closed position to the open position, a delay fluid is injected into the lower chamber. As the delay fluid is expelled from the chamber, it delays a return of the piston and valve member to the closed position.