Balanced plug assemblies and pressure regulators having balanced plug assemblies are described herein. A pressure regulator disclosed herein includes a device body defining a fluid passageway between an inlet and an outlet. The device body defines a channel between the fluid passageway and a pressure sense chamber. The pressure regulator includes a seat in the fluid passageway, a stem having a flange, and a plug coupled to the stem. The pressure regulator also includes a stem guide disposed in the channel of the device body. The flange of the stem disposed in a balance chamber of the stem guide and divides the balance chamber into a first balance chamber portion and a second balance chamber portion. The stem guide at least partially forms a balance passage that fluidly couples the pressure sense chamber and the second balance chamber portion.

A pressure actuated water shutoff valve is presented. The shutoff valve comprises an upper housing and a lower housing where the upper housing is coupled to the lower housing. The lower housing has a water inlet and a water outlet with a flow passage therebetween. The lower housing includes a plunger seat configured to receive a shutoff plunger. The upper housing includes an chamber having a piston bore in which reciprocates an piston, coupled to the shutoff plunger. In response to a first pressure condition, the piston lifts the shutoff plunger off its seat allowing water to flow through the lower housing. In response to a second pressure condition, a biasing spring seals the plunger against its seat, shutting off water flow through the valve.

A regulator may include an inlet from which a high-pressure fluid is introduced, a valve seat provided at the inlet, and a pressure regulating valve body. The fluid may pass an opening between the valve seat and the valve body formed with a communication passage to a pressure regulating chamber. A load generated by pressure of pressure-regulated fluid acting on a piston unit joined to the valve body may be balanced with a load by a pressure regulating spring in an atmosphere chamber provided coaxially in parallel with the pressure regulating chamber on an opposite side of the piston unit. Fluid pressure of the pressure regulating chamber may be controlled by changing an opening area between a valve-seated seat and the valve body. The valve seat holding the valve-seated seat may be installed on an elastic member via a buffer having a sliding performance.

A regulator may include an inlet from which a high-pressure fluid is introduced, a valve seat provided at the inlet, and a pressure regulating valve body. The fluid may pass an opening between the valve seat and the valve body formed with a communication passage to a pressure regulating chamber. A load generated by pressure of pressure-regulated fluid acting on a piston unit joined to the valve body may be balanced with a load by a pressure regulating spring in an atmosphere chamber provided coaxially in parallel with the pressure regulating chamber on an opposite side of the piston unit. Fluid pressure of the pressure regulating chamber may be controlled by changing an opening area between a valve-seated seat and the valve body. The valve seat holding the valve-seated seat may be installed on an elastic member via a buffer having a sliding performance.

A pressure relief module, such as a rupture disk module or a burst panel module, is disclosed. A pressure relief module may comprise a first membrane (10) configured to seal an opening of a contained system and configured to burst open when a pressure in the contained system reaches a predetermined burst pressure. A second membrane (20) may be joined to the first membrane to form a membrane interspace (30) with the first membrane. The membrane interspace (30) may be configured to prevent a backpressure in the contained system from changing the burst pressure required to burst open the first membrane (10). A pressure relief module may provide advantages for a low-pressure enclosure and/or to provide temperature stability and/or backpressure stability.

A vacuum-based energy-saving large-capacity precision pressure regulation valve includes a base valve seat, a middle valve seat, and a pressure regulation seat. The base valve seat includes a main channel that receives a primary-side pressure and a secondary-side pressure to flow therein and includes a valve port piston arranged in the base valve seat to form a valve port opening. The valve port piston is rotatably coupled to a sealing straight rod that is coupled to a main diaphragm. The main diaphragm is clamped between the middle valve seat and the base valve seat to form a vacuum pressure chamber. A balance diaphragm is clamped between the middle valve seat and the pressure regulation seat. An atmosphere passage is connected to a space below the balance diaphragm. A guide passage and a feedback passage are in communication with the vacuum pressure chamber and the main channel.

A vacuum-based energy-saving large-capacity precision pressure regulation valve includes a base valve seat, a middle valve seat, and a pressure regulation seat. The base valve seat includes a main channel that receives a primary-side pressure and a secondary-side pressure to flow therein and includes a valve port piston arranged in the base valve seat to form a valve port opening. The valve port piston is rotatably coupled to a sealing straight rod that is coupled to a main diaphragm. The main diaphragm is clamped between the middle valve seat and the base valve seat to form a vacuum pressure chamber. A balance diaphragm is clamped between the middle valve seat and the pressure regulation seat. An atmosphere passage is connected to a space below the balance diaphragm. A guide passage and a feedback passage are in communication with the vacuum pressure chamber and the main channel.

A regulator may include a fuel inlet from which a high-pressure fluid is introduced, a valve seat provided at the fuel inlet, and a pressure regulating valve body. The fluid may pass an opening between the valve seat and the pressure regulating valve body formed with a communication passage to a pressure regulating chamber provided to face a valve-seated seat arranged on the pressure regulating chamber side of the valve seat. A load generated by pressure of pressure-regulated fluid acting on a piston unit joined to the pressure regulating valve body may be balanced with a load by a pressure regulating spring in an atmosphere chamber provided coaxially in parallel with the pressure regulating chamber on an opposite side of the pressure regulating chamber of the piston unit. Fluid pressure of the pressure regulating chamber may be controlled by changing an opening area between the valve-seated seat and the pressure regulating valve body. The valve seat holding the valve-seated seat may be installed on an elastic member via a buffer having a sliding performance for automatic alignment to enable uniform contact between the pressure regulating valve body and valve-seated seat.

A relief valve device includes: a valve housing that includes a communication passage, which communicates between a first pressure chamber and a second pressure chamber, and a relief chamber, which is configured to communicate with the second pressure chamber; a partition wall that is formed in an inside of the valve housing and partitions between the communication passage and the relief chamber; a first valve member that is configured to block and enable flow of fluid between the first pressure chamber and the communication passage; a first urging member that urges the first valve member; a second valve member that is configured to block and enable flow of the fluid between the second pressure chamber and the relief chamber; and a second urging member that urges the second valve member.

A relief valve device includes: a valve housing that includes a communication passage, which communicates between a first pressure chamber and a second pressure chamber, and a relief chamber, which is configured to communicate with the second pressure chamber; a partition wall that is formed in an inside of the valve housing and partitions between the communication passage and the relief chamber; a first valve member that is configured to block and enable flow of fluid between the first pressure chamber and the communication passage; a first urging member that urges the first valve member; a second valve member that is configured to block and enable flow of the fluid between the second pressure chamber and the relief chamber; and a second urging member that urges the second valve member.