A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits, each kit comprising a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A fluid end assembly comprising: a housing, valves, seals, seats, springs, plungers, plunger packing, and other associated parts, paired with a suction manifold that facilitates fluid feeding through a centrally located external suction intake. The suction manifold of this invention is designed to preserve fluid energy that will ensure complete filling of the cylinder in extreme pumping conditions. The suction manifold utilizes a chamber design positioned immediately below the suction valves, eliminating all connecting ducts. The design of the manifold of this invention can be easily fabricated utilizing commercially available steel plate, pipe, and pipe fittings.

A metering valve is installed in a feed passage that supplies low pressure fuel, which is fed from a feed pump, to a pressurizing chamber. The metering valve adjusts a discharge amount of the low pressure fuel discharged from the pressurizing chamber. A first pressure regulating valve is opened in a case where a pressure of the low pressure fuel becomes equal to or larger than a first preset pressure. A second pressure regulating valve is opened in a case where the pressure of the low pressure fuel becomes equal to or larger than a second preset pressure. The first pressure regulating valve and the second pressure regulating valve are configured such that a degree of responsiveness of valve opening and closing of the second pressure regulating valve is higher than a degree of responsiveness of valve opening and closing of the first pressure regulating valve.

A metering valve is installed in a feed passage that supplies low pressure fuel, which is fed from a feed pump, to a pressurizing chamber. The metering valve adjusts a discharge amount of the low pressure fuel discharged from the pressurizing chamber. A first pressure regulating valve is opened in a case where a pressure of the low pressure fuel becomes equal to or larger than a first preset pressure. A second pressure regulating valve is opened in a case where the pressure of the low pressure fuel becomes equal to or larger than a second preset pressure. The first pressure regulating valve and the second pressure regulating valve are configured such that a degree of responsiveness of valve opening and closing of the second pressure regulating valve is higher than a degree of responsiveness of valve opening and closing of the first pressure regulating valve.

A suction cover assembly for a frac pump includes a suction cover having an annular base flange defining a sealing interface proximate to the base flange. The suction cover is dimensioned to be accommodated within a bore well of a fluid cylinder in the pump. An annular seal is seated on the sealing interface proximate to the base flange of the suction cover.

A valve member for an inlet or outlet valve assembly of a reciprocating pump assembly includes a valve body and a seal member. The valve body comprises a first body surface and a second body surface that extend circumferentially about the valve body. The valve body defines a body axis and an annular cavity. The seal member is positioned at least partially within the annular cavity of the valve body such that an outer seal portion of the seal member extends between the first body surface and the second body surface of the valve body. The outer seal portion of the seal member comprises a first seal surface and a second seal surface. The first body surface, the first seal surface, and the second seal surface extend at different angles relative to the body axis.

A pump fluid end comprising: a reciprocating element disposed at least partially within a reciprocating element bore of the pump fluid end; a discharge valve assembly; a suction valve assembly coupled with a front end of the reciprocating element; and a suction valve stop, wherein the suction valve stop is positioned within the reciprocating element bore such that the suction valve stop contacts and applies a closing force to the suction valve assembly when the suction valve assembly is stuck open at the end of a discharge stroke of the reciprocating element.

A valve assembly comprising a valve seat, a valve body, a valve spring, and a valve guide, wherein the valve seat and/or a valve seat housing in which the valve seat is seated comprises a plurality of grooves; wherein the valve body comprises a first side comprising a valve seat contact surface, and a second side comprising a coupler actuating feature; and wherein the valve guide comprises a coupler, and a plurality of wings, wherein the valve guide comprises a valve guide end distal the coupler, wherein, when the valve guide is coupled to the valve body via the coupler, the valve guide end distal the coupler extends a greater radial distance from the central axis of the valve body than the plurality of wings, and wherein the valve guide can be coupled to or decoupled from the valve body via the coupler by actuating the coupler actuating feature.

A pump fluid end comprising a discharge valve assembly comprising a discharge valve seat and a discharge valve body, a suction valve assembly comprising a suction valve seat and a suction valve body, and a reciprocating element, wherein an inside diameter of the discharge valve seat is greater than an outside diameter of the suction valve body, the suction valve seat, the reciprocating element, or a combination thereof.

A packing assembly for a pump fluid end comprising: a packing screw; a packing carrier; and a packing, wherein the packing screw, the packing carrier, and the packing are each cylindrical with a width measured along a central axis thereof that is less than a minimum spacing distance of a pump comprising the pump fluid end and a pump power end, wherein the pump fluid end comprises a reciprocating element bore in which a reciprocating element can be reciprocated via the pump power end via connection of the reciprocating element to a reciprocating element adapter coupled with a pushrod and crankshaft of the pump power end, wherein the minimum spacing distance is an axial distance measured along the central axis between a back of the pump fluid end and a front end of the reciprocating element adapter when the crankshaft of the pump power end is at top dead center.