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 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 relief valve includes: a housing; a plunger movable to each of a closed position and an open position; a differential pressure chamber; a spring member; a piston; and a damping chamber. The plunger includes a first damping passage penetrating the plunger and bringing an area outside the plunger and a through passage into communication. The piston includes a second damping passage penetrating the piston and bringing an area inside the piston and the damping chamber into communication. A communication space connected to each of the first damping passage and the second damping passage is formed between the plunger and the piston.

A valve includes a housing, in which a first valve body is accommodated so that it is moveable in a direction of a longitudinal axis, a first valve seat configured to be closed by the first valve body and arranged on the housing, a first fluid flow path extending from a first connection via the first valve seat to a second connection, a second valve seat closeable by a moveable second valve body, the second valve body formed separately from the first valve body, a second fluid flow path extending from the first connection via a bypass duct in the first valve body, onwards via the second valve seat to the second connection, so that pressure at the first connection is limited upwardly by the first and the second valve body in that hydraulic fluid is led to the second connection via the first fluid flow path.

A main stage in-line pressure control cartridge. The cartridge selectively controls flow in-line in the same direction as opposed to directing flow at a 90 degree angle like other cartridges. A tubular poppet can be mounted into a body and has a sliding control sleeve that can expose radial holes in the poppet to an open position and to seal the radial holes in a closed position. The cartridge can be configured in numerous ways in order to serve many functions, such as a pressure relief valve, a counterbalance valve, and a flow control valve. The cartridge can also be configured to allow or prevent reverse flow.

A main stage in-line pressure control cartridge. The cartridge selectively controls flow in-line in the same direction as opposed to directing flow at a 90 degree angle like other cartridges. A tubular poppet can be mounted into a body and has a sliding control sleeve that can expose radial holes in the poppet to an open position and to seal the radial holes in a closed position. The cartridge can be configured in numerous ways in order to serve many functions, such as a pressure relief valve, a counterbalance valve, and a flow control valve. The cartridge can also be configured to allow or prevent reverse flow.

A pilot-operated relief valve assembly can include a relief valve, and a pressure detection assembly. A valve lift factor or indicator of relief flow can be determined based on pressure measurements gathered by the pressure detection assembly.

A pilot-operated relief valve assembly can include a relief valve, and a pressure detection assembly. A valve lift factor or indicator of relief flow can be determined based on pressure measurements gathered by the pressure detection assembly.

A pilot-operated relief valve assembly can include a relief valve, and a pressure detection assembly. A valve lift factor or indicator of relief flow can be determined based on pressure measurements gathered by the pressure detection assembly.

A pilot-operated relief valve assembly can include a relief valve, and a pressure detection assembly. A valve lift factor or indicator of relief flow can be determined based on pressure measurements gathered by the pressure detection assembly.