Abstract: An ultra high pressure fluid end for a reciprocating pump. The pump fluid end has a built-in accumulator characterized by an annular volume chamber defined in a body of the pump end. There may be a plurality of such chambers which are interconnected by a discharge manifold which is also in communication with an outlet of the body. The pump fluid end also uses frictional clamping to connect the pump plunger to the drive end of the pump. The frictional clamping includes a collet assembly comprising a split collet positioned around an end of the plunger, a collet hub disposed around the collet, and an adapter adjacent to the collet hub. Fasteners are used for clamping the collet hub to the adapter and thereby causing the collet to clampingly or grippingly engage the plunger. Coaxial inlet and outlet valves are provided in the body. A pressure retainer is disposed in the body around the plunger, and packing is used to seal between the plunger and the pressure retainer.

Abstract: A back pressure regulating valve for ultra high pressures. The valve is designed for use in throttling ultra high pressure pumps, such as those used in fluid jetting systems. The valve has an elongated tapered poppet which fits in an elongated tapered seat such that an elongated, annular tapered flow path is defined therebetween. The flow path preferably has a length greater than a diameter of the poppet, such as approximately ten times the maximum diameter. Also in the preferred embodiment, a minimum annular tapered flow path is defined between the seat and poppet even when the poppet is in an unactuated position. Biasing is provided by a gas filled pressure chamber acting on an actuator piston. The piston at least partially defines a damping chamber, and an orifice is provided between the damping chamber and the pressure chamber so that movement of the piston is damped as it is moved in a direction tending to reduce the volume of the pressure chamber.

Abstract: A pumping apparatus comprises a fluid end cylinder carrying a double-acting piston which is reciprocated by a hydraulic servo actuator to provide an expanded flow range ability for metering fluids. The hydraulic servo actuator comprises: a hydraulic cylinder carrying a drive piston connected to the fluid end piston; a servo valve; a position transducer; and a microprocessor-based controller. The controller is programmed to accommodate accleration and deceleration of the extend and retract phases of a pump cycle to maintain constant average flow rate out of the fluid end. A control apparatus for controlling a pump and a related method are also disclosed.