A miniature poppet valve assembly for a high-speed compressor, the miniature poppet valve assembly includes a plurality of miniature poppets, each characterized by a stem and a head with a maximum head diameter of no more than 0.9 inches; a cage having a plurality of counter bores disposed therein, each counter bore disposed for receipt of a poppet; and a seat plate overlying the cage, the seat plate including a plurality of through bores axially aligned with the counter bores of the cage. Each counter bore includes a chamfered edge against which the head of the poppet seats, thereby forming a seal. The chamfered edged is provided with a chamfer angle of approximately 30 degrees. In one embodiment, poppet heads have a convex head surface and are shaped so that the tangent angle at the point of contact between the edge and the head is approximately 30 degrees.

A valve member assembly includes a housing, a check valve assembly, and a float valve assembly. The housing is a cup, a retainer and a bonnet releasably secured together. The check valve assembly is positioned within the cup, and the float valve assembly is positioned between the bonnet and the retainer. The valve member assembly can be easily assembled and inserted into a valve body.

Valves for relieving pressure from high-pressure fluid systems have a valve fitting and a valve actuator. The pressure relief valve is normally shut and is adapted to open at a relief fluid pressure. It comprises a valve fitting and an actuator. The actuator has a valve stem, a spring, and an electromagnet. The stem is coupled to a valve body and mounted for linear reciprocation. The spring applies a mechanical force that biases the stem to place the valve in a normally shut state, but allows the valve to open at a first fluid pressure below the relief pressure. The electromagnet applies a magnetic force that, together with the mechanical force, holds the valve in an operationally shut state at a second fluid pressure above the relief pressure. The valve may be opened at fluid pressures above the first fluid pressure by de-energizing the electromagnet at the relief pressure.

A fluid flow throttle valve that keeps the pressure of a fluid flow pumped into a system by a high-pressure pump constant and that is particularly suitable as a reject valve for maintaining the system pressure of a reverse osmosis device at a pressure level of <20 bar. The flow pressure is regulated by a spring-actuated cone that is partially within the outflow channel of the throttle valve at any given time. A motion restrictor is supported to the wider end of the cone such that in its lowest position, the cone permits a bypass flow of a predetermined volume up to the target pressure of the system. As the flow volume increases further and the cone rises as a result, the force exerted on the restrictor member by the flow pressure contributes to preventing the valve from closing.