A first relief valve chamber (3) of a main relief valve (10) and a second relief valve chamber (7) of an auxiliary relief valve (11) are provided in series in a valve case 1. The first relief valve chamber (3) includes a valve seat chamber (4) at the right and a valve chamber (5) at the left. A first valve member (30) in the valve chamber (5) is biased toward a valve seat member (18) in the valve seat chamber (4) by a first relief spring (40). A second valve member (48) in the second relief valve chamber (7) is biased toward a second valve seat (47) by a second relief spring (50).

A pressure adjuster may connect with a supply path connecting a fuel supply device and a fuel use device. The pressure adjuster may comprise a pressure chamber communicating with the supply path located closer to the fuel supply device than a check valve of the supply path, a communication chamber communicating with the supply path located closer to the fuel use device than the check valve, a valve member including a first pressure-receiving surface and switching between an open state and a closed state by pressure of fuel inside of the pressure chamber at the first pressure-receiving surface, a discharge path communicating with the communication chamber and configured to discharge fuel flowing from the communication chamber to outside of the casing when the valve member is in the open state, and a constriction portion disposed in the discharge path and constricting a cross section area of the discharge path.

A fluid pressure regulating unit, comprises a fluid inlet port, a fluid outlet port, a valve comprising a movable valve part, wherein the movable part comprises at least one fluid pressure balancing means and wherein the at least one pressure balancing means comprises a tapered surface, and a main valve biasing means. The main valve biasing means biases said valve in the direction of an open position. An auxiliary valve biasing means is provided, biasing the valve in the direction of a closed position. Wherein essentially every surface part, being in fluid connection to the fluid inlet port and having a surface normal at least partially in parallel to the moving direction of the moving part of the valve, is balance by a balancing surface part.

A pressure relief device for a double isolation valve comprises a body with a valve cavity. The valve body has a pocket formed therein. A disc is disposed in the central section of the pocket. The disc is interposed between two spring-actuated seats. Each of the seats is in fluid communication with opposing valve sides. The pocket central section is in fluid communication with the valve body cavity. Each of the seats is provided with two different types of gaskets in series. In operation, reverse pressure causes retraction of the seats, thereby relieving valve body cavity overpressure.

A pressure valve is configured to be selectively coupled to a vessel and includes a housing including a vent aperture configured to provide fluid communication between an internal cavity of the housing and ambient air surrounding the pressure valve, an accessory aperture configured to couple an accessory to the housing, and a seal seat positioned within the internal cavity fluidly between the vent aperture and the accessory aperture. The pressure valve includes a pressure control assembly including a seal configured to break a sealing engagement with the seal seat to provide fluid communication between the vessel and the vent aperture in response to a desired positive pressure being reached within the vessel. The seal is configured to break the sealing engagement with the seal seat to provide fluid communication between the vessel and the vent aperture in response to an operator moving an actuator of the pressure control assembly.

A valve assembly configured for use with an inflatable product, such as a mattress, chair, pool, spa, float, or another suitable inflatable product. The valve assembly includes a first valve component that serves as an opening for inflation and/or deflation of the inflatable product, and a second valve component that serves as an opening for deflation or decompression of the inflatable product.

A pressure valve is configured to be selectively coupled to a vessel and includes a housing including a vent aperture configured to provide fluid communication between an internal cavity of the housing and ambient air surrounding the pressure valve, an accessory aperture configured to couple an accessory to the housing, and a seal seat positioned within the internal cavity fluidly between the vent aperture and the accessory aperture. The pressure valve includes a pressure control assembly including a seal configured to break a sealing engagement with the seal seat to provide fluid communication between the vessel and the vent aperture in response to a desired positive pressure being reached within the vessel. The seal is configured to break the sealing engagement with the seal seat to provide fluid communication between the vessel and the vent aperture in response to an operator moving an actuator of the pressure control assembly.

An example counterbalance valve includes: a poppet configured to be subjected to a fluid force by fluid received at a first port, and a fluid force by a pilot pressure fluid signal received at a pilot port; a first setting spring disposed in a first chamber and applying a first biasing force on the poppet; and a second setting spring disposed in a second chamber and applying a second biasing force on the poppet, wherein the first chamber and the second chamber are vented to an external environment of the counterbalance valve, wherein the second setting spring is in parallel with the first setting spring such that an equivalent biasing force acting on the poppet in the distal direction comprises a sum of the first biasing force and the second biasing force.

A sub-machine of a soda fountain with an adjustable exhaust velocity includes a main body, a water bottle connector, a housing, a taper ring, a bottom cover, a positioning seat, an air inlet assembly, an air nozzle rod, an exhaust valve, a soda bottle, a connecting seat, an exhaust knob and key, the connecting seat covers an upper opening of an exhaust valve cavity, the valve rod passes through a guide hole a lower surface of the exhaust key is attached to a flat seat plate part; a circular body part extends into an arc-shaped part, the exhaust key is nested into an exhaust key cavity, and a handle part extends out from a guide notch; the exhaust key is in sliding fit with an inclined surface part. Due to this structure, the handle part is operated to rotate the exhaust knob, so as to perform exhaust and adjust the exhaust velocity.

A pressure valve includes a housing having bottom portion defining a bottom opening configured to be in communication with a vessel and a sidewall defining an internal cavity. The housing includes a vent aperture configured to provide fluid communication between the internal cavity and ambient air surrounding the pressure valve and an accessory aperture configured to couple an accessory to the housing. A seal seat is positioned within the internal cavity fluidly between the vent aperture and the bottom opening. A pressure control assembly is coupled to the housing. The pressure control assembly breaks a sealing engagement with the seal seat to provide fluid communication between the vessel and the vent aperture in response to a desired positive pressure being reached within the vessel or in response to a negative pressure being reached in the vessel. The accessory aperture is positioned between the bottom opening and the seal seat.