The present invention teaches a gearbox expansion cap that allows a gearbox unit to breathe to atmosphere while preventing the ingress of water or other materials into the gearbox or gearbox oil. According to a first preferred embodiment, the expansion cap of the present invention includes a pressure relief plug to control gearbox pressures. Additionally, the present invention teaches air channels enclosed within a gearbox casting which mate with air channels provided within the expansion cap to channel air from the expansion cap into the atmosphere.

A relief valve has a valve body, a plunger assembly coupled to the valve body for selectively opening and closing the relief valve, and a support member secured to the valve body. A lockout lever is against the support member, forming a vertex. A spring rod is coupled to the lockout lever, and a spring is coupled to the spring rod, providing a bias force against the plunger assembly to normally close the relief valve. In a lockout position, the lockout lever is moved to pivot on the vertex against the support member to further compress the spring, which increases the bias force and, in turn, a cracking pressure of the relief valve.

A pressure relief valve may comprise a housing, a disk, and a seal. The disk may be configured to deflect relative to the housing. The seal may form a sealing interface with at least one of the housing or disk. The pressure relief valve may be coupled to an inflatable slide or an aspirator.

A valve for a vacuum apparatus includes a first housing element and a second housing element wherein an outer chamber is defined by the first housing element and the second housing element. The first housing element has a first opening and the second housing element has a second opening in fluid communication with the first opening via the outer chamber. An inner chamber is defined by the first housing element and the second housing element wherein a membrane is disposed in the inner chamber. A sealing element is connected to the membrane and is moveable from a first position to a second position wherein in the first position the sealing element closes the first opening in a leak-tight manner and in the second position the sealing element opens the first opening to allow a gaseous medium to flow through the valve.

The arrangement includes a pressure relief hatch for closing an opening in a wall in an electric cabinet, which. includes a body having an outer surface, an opposite inner surface, an outer perimeter, and a thickness. The body includes a centre portion with a first thickness, an intermediate portion with a second thickness, and an outer portion with a third thickness. The first thickness is greater than the third thickness and the second thickness decreases in a radially outward direction from the first thickness to the third thickness. A spring keeps the pressure relief hatch in a closed position in the opening during normal operation of the electric cabinet.

A relief valve device having a spring, a valve bonnet, a valve stem, a disc holder, a valve disc, a huddling chamber, a blowdown ring, and a nozzle. In the valve device, the valve disc is positioned above the nozzle; the spring is disposed in the valve bonnet; the spring surrounds the valve stem such that a longitudinal axis of the spring and a longitudinal axis of the valve stem are coaxial; the disc holder surrounds an outer periphery of the valve disc and is adjacent and in direct contact with a surface of the valve disc around an entire perimeter of the valve disc; the blowdown ring is disposed at a top section of the nozzle; a bottom section of the nozzle is connected to a bottom surface of a valve body and the top section of the nozzle is connected to the valve disc; and the disc holder is filled with oil.

A valve spring seat sleeve, a valve assembly, and a plunger pump are disclosed. The valve spring seat sleeve includes a cylindrical hollow structure, a first fluid hole, a first notch and a second notch; the cylindrical hollow structure includes a plunger passage; the first fluid hole passes through a sidewall of the cylindrical hollow structure and communicated with the plunger passage; the first notch and the second notch are located on a side of the cylindrical hollow structure opposite to the first fluid hole; the cylindrical hollow structure includes a first end portion, a second end portion and an intermediate portion, a center of the first fluid hole is located at the intermediate portion, the cylindrical hollow structure further includes a spring mounting portion located between the first notch and the second notch.

A damped check valve having multi-pressure operation is provided. The check valve includes a liner with a poppet movable within the liner. The liner defines a flow passage aligned along a longitudinal axis defined by the liner. A biasing element is operably coupled between the poppet and the liner to bias a first flow face of the poppet against an annular seat. The first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. There is a sufficient diametrical clearance between the poppet and the liner which allows for flow control at pressures which are less than the initial opening pressure.

A relief valve device having a spring, a valve bonnet, a valve stem, a disc holder, a valve disc, a huddling chamber, a blowdown ring, and a nozzle. In the valve device, the valve disc is positioned above the nozzle; the spring is disposed in the valve bonnet; the spring surrounds the valve stem such that a longitudinal axis of the spring and a longitudinal axis of the valve stem are coaxial; the disc holder surrounds an outer periphery of the valve disc and is adjacent and in direct contact with a surface of the valve disc around an entire perimeter of the valve disc; the blowdown ring is disposed at a top section of the nozzle; a bottom section of the nozzle is connected to a bottom surface of a valve body and the top section of the nozzle is connected to the valve disc; and the disc holder is filled with oil.

An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.