A multi-function valve is disclosed. The multi-function valve including a housing having an internal bore therein; a spool valve positioned in the internal bore, the spool valve configured to seal and direct a flow of compressed air and exhaust; and a spring operably connected to the spool valve, the spring biasing the spool valve in a normally open exhausting position.

Valve assemblies for reciprocating downhole pumps are provided. The valve assembly may comprise: a flow cage comprising a housing and a tubular insert; an annular valve seat positioned below the tubular insert; and an elongated sealing member positioned above the annular valve seat and at least partially received into the tubular insert. In some embodiments, the elongated sealing member may be more stable and may more securely engage the valve seat compared to spherical valve balls. Related methods are also provided.

A pump assembly is disclosed. The pump assembly including an outer casing having a first end, an opposing second end, and a cavity therein; a discharge tube positioned in the cavity and exiting the first end of the outer casing; a check valve positioned in the cavity and operably connected to the discharge tube by a coupling; and a multi-float control assembly positioned in the cavity, the multi float control assembly including a bottom float check valve operably connected to the discharge tube by the coupling and an upper float check valve connected to a vent exiting the first end of the outer casing.

Described is a check valve having a valve housing, a valve seat, a ball and a spherical loading element. The valve seat is disposed proximate to a first end of the bore. The ball is disposed in the bore and is movable between a closed position in which the ball is received against the valve seat and prevents a flow of fluid through the bore and an open position in which the ball is displaced from the valve seat and allows fluid to flow through the bore. The spherical loading element is disposed in the bore and is movable between the ball and the second end of the bore. The spherical loading element applies a supplemental force to move the ball against the valve seat during closing of the check valve. The check valve provides a low and predictable cracking pressure which does not vary significantly between similarly manufactured valves.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

A pump having significantly minimized or no ullage for pumping material (fluid or aggregate).

A valve device (2), of a pneumatically actuatable friction clutch engageable by spring force, includes at least one inlet valve (16, 18) connected on the input side to a pressurized supply line and on the output side to an actuating cylinder of the friction clutch. A pressure-sustaining valve (20, 28) is upstream or downstream of the inlet valve and is designed as a check valve closing in the backflow direction. The pressure-sustaining valve is a springless check valve and includes a housing ring (22, 30) having a retaining basket (36), a closing element (24, 32), and a valve seat (26, 34). The closing element, in the depressurized state and with a positive pressure gradient is held in the retaining basket (36) of the housing ring (22, 30) and, with a negative pressure gradient is pressed out of the retaining basket (36) and against the valve seat (26, 34).

A pump assembly is disclosed. The pump assembly including a pump having an outer casing having a first end, an opposing second end, and a cavity therein and a multi-function valve connected to the first end of the pump. The pump further including a discharge tube positioned in the cavity and exiting the first end of the outer casing; a check valve positioned in the cavity and operably connected to the discharge tube by a coupling; and a multi-float control assembly positioned in the cavity, the multi float control assembly including a bottom float check valve operably connected to the discharge tube by the coupling and an upper float check valve connected to a vent exiting the first end of the outer casing.

Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly to allow or stop a flow for use with enclosed environment includes a housing having, an inlet disposed at a first end of the housing fluidly coupled to environment surrounding housing, an outlet disposed at a second end of housing fluidly coupled to enclosed environment, and an interior volume divided into a first zone, a second zone, and a third zone, a first valve having a first valve seat and a first sealing member urged by an existing force between a closed or open position; and a second valve having a second valve seat and a second sealing member urged by an existing force between a closed or open position.

Apparatuses and methods for pressure regulating check valve assemblies are described. In an example, the check valve assembly comprises a housing defining a fluid passage having a fluid inlet side and a fluid outlet side. A lift check valve positioned within the fluid passage oriented to restrict fluid flow from the fluid inlet side and a second check valve positioned within the fluid passage oriented to restrict fluid flow from the fluid outlet side. A flow dampener is positioned within the fluid passage and between the first and second check valves.