In one aspect, valve seats are described herein having structure and design addressing degradative stresses encountered by the seats during installation and operation in fluid ends. In some embodiments, a valve seat for use in a fluid end comprises a first section for insertion into a fluid passageway of the fluid end and a second section extending longitudinally from the first section, the second section comprising a frusto-conical valve mating surface, wherein the second section is encased in a ring imparting a compressive stress condition to the second section.

A pressure booster constituting a cylinder apparatus is provided with a first piston and a second piston that are coupled to each other by a rod. A connection member provided to the second piston is configured so as to be displaceable from a connection position to a blocking position as a result of the connection member making contact with a cylinder body when the second piston is displaced in a direction where a boosting chamber contracts, and so as to be displaceable from the blocking position to the connection position as a result of the connection member making contact with the cylinder body when the second piston is displaced in a direction where the boosting chamber expands.

A pressure booster constituting a cylinder apparatus is provided with a first piston and a second piston that are coupled to each other by a rod. A connection member provided to the second piston is configured so as to be displaceable from a connection position to a blocking position as a result of the connection member making contact with a cylinder body when the second piston is displaced in a direction where a boosting chamber contracts, and so as to be displaceable from the blocking position to the connection position as a result of the connection member making contact with the cylinder body when the second piston is displaced in a direction where the boosting chamber expands.

A valve assembly having a valve body, a hardened insert, a sealing insert, and a carrier. The hardened insert is cylindrical and comprises a primary sealing surface. The sealing insert is cylindrical and comprises an initial sealing surface. The carrier has an inside surface. The hardened insert and the sealing insert are coupled to the carrier. In a closed configuration of the valve assembly, the valve body contacts the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to prevent fluid flow through the valve assembly, and in an open configuration, the valve body is separated from the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to allow fluid flow through the valve assembly.

A valve assembly having a valve body, a hardened insert, a sealing insert, and a carrier. The hardened insert is cylindrical and comprises a primary sealing surface. The sealing insert is cylindrical and comprises an initial sealing surface. The carrier has an inside surface. The hardened insert and the sealing insert are coupled to the carrier. In a closed configuration of the valve assembly, the valve body contacts the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to prevent fluid flow through the valve assembly, and in an open configuration, the valve body is separated from the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to allow fluid flow through the valve assembly.

A three-stage compression air pump includes a pump head and a pumping device. The pumping device includes first and second cylinders and a plunger. The first cylinder is connected with the pump head and coupled to a first piston moving in the second cylinder. The second cylinder includes a first end cap and a second end cap respectively coupled to the two ends thereof The first cylinder is inserted through the first end cap. The second end cap defines an orifice allowing outside air to flow into the second cylinder and includes a one-way valve preventing the air in the second cylinder from flowing outside the three-stage compression pump. The plunger is inserted in and movably coupled to the first cylinder and coupled to a second piston moving in the first cylinder and connected with the second end cap. The plunger is inserted through the first piston.

A valve assembly having a valve body, a hardened insert, a sealing insert, and a carrier. The hardened insert is cylindrical and comprises a primary sealing surface. The sealing insert is cylindrical and comprises an initial sealing surface. The carrier has an inside surface. The hardened insert and the sealing insert are coupled to the carrier. In a closed configuration of the valve assembly, the valve body contacts the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to prevent fluid flow through the valve assembly, and in an open configuration, the valve body is separated from the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to allow fluid flow through the valve assembly.

A valve assembly having a valve body, a hardened insert, a sealing insert, and a carrier. The hardened insert is cylindrical and comprises a primary sealing surface. The sealing insert is cylindrical and comprises an initial sealing surface. The carrier has an inside surface. The hardened insert and the sealing insert are coupled to the carrier. In a closed configuration of the valve assembly, the valve body contacts the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to prevent fluid flow through the valve assembly, and in an open configuration, the valve body is separated from the primary sealing surface of the hardened insert and the initial sealing surface of the sealing insert to allow fluid flow through the valve assembly.

The lightweight triplex plunger pump provides high pressure and flow output in a compact unit size. The lightweight triplex plunger pump can be used in a number of machines where there is a need for high pressure/high flow ultra-portable device. The lightweight triplex plunger pump of the present invention is mostly comprised of a crank casing having a crankshaft and a plunger assembly which are enclosed within the crank casing; as well as a pump head or a fluid chamber for handling the fluid. The pump head further includes a suction manifold connected with the fluid reservoir through an inlet; a discharge manifold that pumps out the pressurized fluid through outlet; and a pump chamber for compressing the pump using the reciprocating movement of the plunger. Both the suction manifold and the discharge manifold includes openings that open within the pump chamber and valve configured within said opening. The movement of the plunger causes valves to open or close to suck the fluid from the suction manifold into the pump chamber and pump out the pressurized fluid out of the pump chamber into the discharge manifold.

The lightweight triplex plunger pump provides high pressure and flow output in a compact unit size. The lightweight triplex plunger pump can be used in a number of machines where there is a need for high pressure/high flow ultra-portable device. The lightweight triplex plunger pump of the present invention is mostly comprised of a crank casing having a crankshaft and a plunger assembly which are enclosed within the crank casing; as well as a pump head or a fluid chamber for handling the fluid. The pump head further includes a suction manifold connected with the fluid reservoir through an inlet; a discharge manifold that pumps out the pressurized fluid through outlet; and a pump chamber for compressing the pump using the reciprocating movement of the plunger. Both the suction manifold and the discharge manifold includes openings that open within the pump chamber and valve configured within said opening. The movement of the plunger causes valves to open or close to suck the fluid from the suction manifold into the pump chamber and pump out the pressurized fluid out of the pump chamber into the discharge manifold.