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.

Abstract: The fluid end of a reciprocating pump contains a plurality of manifold cylinders for pumping fluid. The fluid end has an improved liner assembly with a shaft, a coaxial piston, and a liner with a liner seal on an outward end. The liner and seal abut an inner wall of the manifold to prevent pressurized fluid leakage between the liner and the manifold. The liner is pressed against the manifold by an adjustment mechanism which is mounted to a housing surrounding the pump. The adjustment mechanism is spaced axially away from the manifold wall and allows the liner to self-adjust to the wall without the need for a liner bushing. A support device is provided for assisting in the vertical alignment of the liner assembly prior to the liner being pressed tightly against the manifold wall.