Abstract: A gas meter installation including gas supply plumbing and point of use plumbing will have a gas meter therebetween. A valve can be installed with the gas meter for shutting off the flow of gas to the point of use. This valve is preferably a gate valve mounted with the a gas meter, and can be retrofitted into existing installations, or installed with the new plumbing installation. The valve can be shut off by remote activation for example due to a seismic sensor causing a controller to send a signal to activate the valve. The control can also interact with electricity shut off apparatus, automatic meter reading apparatus and point of use security systems.

Abstract: A remotely-actuated residential water supply cut-off system is disclosed. A remotely-actuated cut-off valve interposed in a residential water line downstream of a pressure-reducing valve. An electronic actuator is mounted on the cut-off valve and is remotely actuated to drive a DC motor in a clockwise or counterclockwise direction to open or close the cut-off valve in response to a received signal. The electronic actuator includes a transceiver, a microcontroller and a motor. The microcontroller drives the motor to open or close the valve in response to a wireless signal received by the transceiver. A handheld transceiver unit sends a signal to the actuator to open or close the cut-off valve, or operate in automatic mode.

Abstract: A methods and system detecting water system leaks provides detecting of water leakage having very low flows. Very low flow leaks are detected by detecting drops in a building water system pressure when the water supply source is disabled. The water system is disabled by an electrically controllable valve, which may be turned off in response to a motion detector that detects that no human activity is present in the building. The rate of pressure drop is used to determine the magnitude of the leak, and multiple thresholds can be used to detect slow leaks versus more serious leaks. A humidity detector may also be incorporated in the system to detect abnormal humidity conditions and shut the electrically controllable valve in response. Appliance current consumption can be detected and used to override motion-sensor based shut-off of the valve, so that water-consuming appliances can continue to operate.

Abstract: A gas shutoff valve having a sensor in cooperation with a magnet to hold a seal mechanism in an open position allowing a flow through a valve body, wherein sufficient disturbance of the valve causes the sensor to sufficiently separate from the magnet to release the seal mechanism to block the flow of gas through the valve. The sensor resides in a sensor housing and means are provided to level the sensor housing to provide consistent operation of the valve when the valve body is not level.

Abstract: The present invention provides a valve assembly adapted to be coupled to a fuel tank of a motorcycle. The valve assembly includes a one-piece valve housing having a rollover valve housing portion at least partially defining a first chamber and a pressure relief valve housing portion at least partially defining a second chamber. The valve assembly also includes a rollover valve positioned in the first chamber and a pressure relief valve positioned in the second chamber.

Abstract: A gas monitoring system that comprises a sensor, a first valve, and a second valve. The sensor is disposed within a sensor housing that has an inlet and an outlet. The sensor generates a signal based on a characteristic of a gas within the housing. The first valve is disposed at the inlet. The second valve is disposed at the outlet. The first valve and the second valve open and close based on an orientation of the sensor housing.

Abstract: A vapor vent/tipping valve has a diaphragm with a bleed therethrough responsive to the differential pressure of bleed flow to control vapor venting to the canister and vapor recirculation to the filler tube. A dip tube causes rising fuel in the tank to close the dip tube and prevent vapor flow to the diaphragm bleed thereby starving the recirculation line and allowing nozzle discharge to create a vacuum in the filler and effect nozzle shutoff. Alternatively, float operated shutoff valves may be employed in the dip tube and vapor vent chamber inlet, the shutoff valves may include inertial members for closing the float valves to afford tipping/rollover protection.

Abstract: A safety valve system includes a control valve connected to a gas meter and intersecting a gas flow path downstream of the gas meter and upstream of an entry point of a building. The control valve is adaptable between open and closed positions based upon received stimuli. A main gas supply line is mated to the control valve and includes auxiliary lines branching to appliances. A plurality of sensors are coupled in series to the appliances and are in communication with the control valve. A mechanism is included for transmitting a control signal to the control valve and for eliminating a fully charged gas line when the stimuli are detected by one of the sensors such that the control valve can allow and restrict gas flow to the appliances during operating and non-operating modes. Each of the sensors generates a unique control signal when the stimuli are detected.

Abstract: A valve comprising a housing accommodating a first and a second outlet port, a first stage float member associated with the first outlet port and a second stage float member associated with the second outlet port. The float members are displaceable within the housing about parallel axes, between an open position and a closed position. The first stage float member at least partially overlaps over the second stage float member.

Abstract: A control valve apparatus for a rotating clutch includes a valve having a spool portion and a mass portion. The spool portion provides a control function to distribute pressure from a static source to a chamber of the clutch. The valve also has a mass associated therewith which is responsive to rotation of the clutch and valve apparatus such that the apply pressure and the centrifugal effective pressure operating on the valve and the mass centrifugal force is compensated for to maintain the pressure at a specific radius of the clutch equal to the static apply pressure of the pressure source independent of rotation speed.

Abstract: An earthquake actuated device includes a flapper-valve adapted to block a gas flow and a micro switch for closing or opening a circuit. A seismic sensor responds to accelerations characteristic of an earthquake. The sensor cooperates with a magnet in a flapper arm to hold the flapper-valve open. When the sensor experiences sufficient motion, the flapper arm is released and the flapper-valve falls onto a seat, thereby closing and blocking the gas flow. The closing of the flapper-valve is further coupled into an actuation of the micro switch, thereby opening or closing the circuit.

Abstract: An improved thermal relief vent for a fuel tank, and a method of manufacturing the same, includes a thermal relief ring that is used to create a mechanical seal within the vent. The thermal relief ring, at room temperature, is crimped in place by use of the vent cap itself. The crimped thermal relief ring creates a mechanical seal between the vent and the vent cap, up until a predetermined thermal relief point, at which time the thermal relief ring will soften and/or yield and release the vent cap from the vent body.

Abstract: A shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism having elongated walls to provide additional leverage when the force strikes the trip fork mechanism that is mounted on a pivoting mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: A microprocessor-based gas meter has fully electronic control, safety cutoff and data communication functions, while remains the same size of a conventional gas meter. The control circuit board in the microprocessor-based gas meter is mounted inside the main body of the gas meter through a mounting slot. The sensors, wires and battery are located in the rest space of the chamber so as to utilize the space of the chamber. When an abnormal situation is detected, the control circuit activates a cutoff valve and shuts off the gas intake. The data communication function is to transfer gas-metering data through telephone lines to the gas company so that the mistakes and cost of manual checking and recording can be eliminated.

Abstract: A gas meter installation including gas supply plumbing and point of use plumbing will have a gas meter therebetween. A valve can be installed with the gas meter for shutting off the flow of gas to the point of use. This valve is preferably a gate valve mounted with the a gas meter, and can be retrofitted into existing installations, or installed with the new plumbing installation. The valve can be shut off by remote activation for example due to a seismic sensor causing a controller to send a signal to activate the valve. The control can also interact with electricity shut off apparatus, automatic meter reading apparatus and point of use security systems.

Abstract: A vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism having elongated walls to provide additional leverage when the force strikes the trip fork mechanism that is mounted on a pivoting mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: A method and system for controlling a household water supply incorporating motion-sensing for determining whether a house is occupied, provides protection of structures and fixtures from water damage due to plumbing failure or other causes. The household water supply is shut-off in conformity with a determination that the household is unoccupied and thereby provides automatic protection from water damage.

Abstract: A vent cap is provided for releasing gas from containers, while preventing spillage of the contents therein when the container is tipped from a vertical position. The vent cap has a ball bearing mounted in a ball bearing containment chamber on the top thereof which, when the container is in an upright vertical position, allows release of gases from the container but, when the container is tipped, allows a piston disposed within the vent cap to close off gas release ducts formed in the vent cap, thus effectively preventing spillage of the containers contents.

Abstract: A fuel blocking valve device includes a housing attached to a fuel tank of a vehicle and having a communication path between an inside and an outside of the fuel tank, a float valve for closing the communication path when fuel flows into the housing, and a two-way valve disposed above the float vale for opening and closing according to an inner pressure of the tank. The two-way valve opens and closes according to a difference between the inner pressure of the fuel tank and an atmospheric pressure. Further, the two-way valve includes a valve member for opening when the vehicle runs and vibrates. The valve member is formed of a spherical member and a cone shape valve seat for opening the communication path when the inner pressure of the fuel tank exceeds a predetermined high level.

Abstract: A vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism having elongated walls to provide additional leverage when the force strikes the trip fork mechanism that is mounted on a pivoting mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: A microprocessor-based gas meter has fully electronic control, safety cutoff and data communication functions, while remains the same size of a conventional gas meter. The control circuit board in the microprocessor-based gas meter is mounted inside the main body of the gas meter through a mounting slot. The sensors, wires and battery are located in the rest space of the chamber so as to utilize the space of the chamber. When an abnormal situation is detected, the control circuit activates a cutoff valve and shuts off the gas intake. The data communication function is to transfer gas-metering data through telephone lines to the gas company so that the mistakes and cost of manual checking and recording can be eliminated.

Abstract: In order to safely close a shut-off device (2) used in a gas supply line (1) in the case of danger, the closing part of said shut-off device is coupled with a pneumatic working cylinder (4) whose actuating piston (3) is maintained in the respective open position of the shut-off device (2) by the accessory pressure of CO2 liquid gas cartridge (5) and against the force of a lock spring (6). Under emergency conditions, a ventilating valve (8) which relieves the pressure form the actuating piston (3) is electronically triggered by a gas sensor (10) positioned in a sensor zone by the inactivation of a securing magnet and the shut-off device (2) is safety closed.

Abstract: A vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism having elongated walls to provide additional leverage when the force strikes the trip fork mechanism that is mounted on a pivoting mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: An automatically actuated regulation system for a natural gas pipeline having flow control unit, a vibration sensor, a gas flow meter, a trigger unit, and a microprocessor. The microprocessor actuates the flow control unit when two conditions are met. First, there must be a vibration which surpasses a predetermined threshold. Second, flow in the natural gas pipeline must have increased over the flow rate before the vibration. The system can be configured to store gas usage data and, in one embodiment, transmit the data to another location through the use of a modem or other communication means.

Abstract: A method and system for controlling a household water supply provides protection of structures and fixtures from water damage due to plumbing failure or other causes. The household water supply is shut-off in conformity with a determination that the household is unoccupied and thereby provides automatic protection from water damage.

Abstract: A high flow rate fuel vapor vent and rollover valve assembly with a float valve that provides a progressive closing of a vapor outlet to control the venting of fuel vapors from a fuel tank and the addition of liquid fuel to the tank. The float closes a portion of the vapor outlet in response to liquid fuel at a first level in a vehicle fuel tank. A body completely closes the vapor outlet in response to rollover attitudes of the vehicle. One or more separate baffles are constructed and arranged to prevent the escape of liquid fuel through the vapor outlet.

Abstract: An automatically closing ambient air device is disclosed having a generally conical passageway, containing an inlet for the flow of fluid from the ambient environment into the passageway and an outlet for the flow of such fluid from the passageway, and having valve means arranged to close fluid flow through the outlet from the passageway which is actuated by buoyant force and/or gravitational force and/or a combination thereof imposed by a weighted element in response to the spacial orientation of the conical wall of the passageway to level.

Abstract: A pressure (1) release valve is disclosed ideally for use on petrol tankers which can rollover in an accident. There is a requirement for such valves both to become sealed in the event of a rollover to prevent the escape of volatile and flammable fluid from within the tanker, and also to allow for the venting of gas above the fluid within the tanker under normal operating conditions. The valve comprises a movable plunger (24) and a fixed seat (32) which can move axially towards and away from each other to open and close the valve. One or other of valve seat and plunger is provided with magnetic inserts (23), while the alternate component is ferromagnetic so that magnetic attraction betwixt the two components acts to bias the valve towards a closed condition.

Abstract: Combination of a float valve for venting a fuel tank allowing venting in the inclined position, preventing the ejection of liquid, fulfilling the OPD and ROV functions and the function of degassing during filling, and of a capacity equipped with a draining system capable of trapping small quantities of liquid fuel entrained with the gases and of returning them to the tank.

Abstract: The invention concerns a ventilating device for a motor vehicle fuel tank wherein a valve (12) is equipped with a ball (20) arranged in a chamber (14) wherein emerges an intake orifice (16) which opens into the center of a lower wall (19) concave upper surface (22) of the chamber (19), the ball (20) being supported on the concave upper surface (22). The invention is characterised in that the slope, relative to the horizontal, of the concave upper surface (22) decreases in the direction radially away from the axis (A1).

Abstract: A vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism that is mounted on a pivoting parallelogram lever mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: A vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude. The vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate, where the ball can be rotated 360° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a pipe that is mounted on a pivoting parallelogram lever mechanism, thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein.

Abstract: The present invention relates to the multifunctional urgent shutoff safety valve for preventing accidents such as gas explosion, fire, etc. in advance. It is installed at the gas supply path. The spool assembly run by earthquake accelerations in case of an earthquake of stronger than a fixed level shuts off the gas circulation path to stop gas supply, or the spool assembly shuts off the gas circulation path to stop gas supply when an excessive amount of gas is flowed out in a short time due to blowing-out of the rear end pipe of the present valve. In the configuration of the multifunctional urgent shutoff safety valve of the present invention, a permanent magnet, which is mounted on the upper end of the spool assembly installed at the valve room in the main body in the vertical state to pen and close the outlet port, is suspended apart from the bottom surface of the pendulum (acceleration sensor) at a fixed interval, when the valve outlet port is open.

Abstract: An automatically actuated regulation system for a natural gas pipeline having flow control unit, a vibration sensor, a gas flow meter, a trigger unit, and a microprocessor. The microprocessor actuates the flow control unit when two conditions are met. First, there must be a vibration which surpasses a predetermined threshold. Second, flow in the natural gas pipeline must have increased over the flow rate before the vibration. The system can be configured to store gas usage data and, in one embodiment, transmit the data to another location through the use of a modem or other communication means.

Abstract: A valve includes a bobbin/valve body, a solenoid and a plunger. The bobbin/valve body is formed in one piece, defines all of the valve's inlet/outlet ports and forms the entire support structure for the solenoid and the plunger. To assemble the valve, a plunger body is inserted into the bobbin/valve body through an end opening into a longitudinal bore and a spring positioned to bias the plunger body to a normally closed position. A pole piece is then inserted through the end opening into the longitudinal bore and attached to the bobbin/valve body. A solenoid coil is wound around a central cylindrical section of the bobbin/valve body, and terminal pins and a flux conductor are attached to the bobbin/valve body. The attachment of the pole piece, the terminal pins, and/or the flux conductor may be accomplished by press-fit and/or swage coupling techniques.

Abstract: A system and method of disabling utility service supplied to a building during and after an earthquake. A shock sensor for sensing seismic activity is provided and a seismic activity threshold is established. Seismic activity is sensed over time and the seismic activity sensed is compared to the seismic activity threshold. When seismic activity exceeds the seismic activity threshold, utility service is cut off to the building.

Abstract: The improved shock actuated sensor is used with shock activation valves which have a shock activation control mechanism. The control mechanism includes a pedestal with a vertical tube disposed thereround and a weight in the form of a ball supported on the pedestal upper end. When a shock or vibration force is experienced the ball is displaced horizontally from a rest position to a side of the control mechanism where it engages the vertical tube that causes the valve to close. The improvement includes a pedestal upper end with a circumferential step to aid the ball in engaging the vertical tube to activate the valve closing. The step allows gravity, in addition to the shock force, to urge the ball to move the vertical tube. The pedestal upper end may also have a recess in the form of an open cylindrical recess to support the ball.

Abstract: An emergency gas line shut-off system for automatically preventing a flow of gas into a structure during the detection of emergency conditions. The emergency gas line shut-off system includes a gas valve for mounting on a gas supply line. The gas valve is electrically connected to a central control assembly for controlling the gas valve. The central control assembly preferably comprises control circuitry for determining when the gas valve should be in a closed condition for preventing the flow of gas into a structure. The control circuitry is mounted in a housing and is electrically connected to a detector for detecting a condition requiring the closed condition of the gas valve. The detector may comprise, for example, a smoke detector for detecting smoke, a carbon monoxide detector for detecting carbon monoxide or an earthquake detector for detecting earthquakes.

Abstract: A crash valve is located in a liquid tight dispenser pan at a gasoline service station to close a conduit conveying gasoline to a gasoline dispensing unit to prevent uncontrolled flow of gasoline in the event a vehicle crashes into the dispensing unit. The dispenser pan collects any leaking gasoline or inflow of water; the presence of gasoline is an obvious safety hazard and the accumulating water may cause electrical or mechanical malfunction of the crash valve. An actuator, responsive to the presence of either water or gasoline in the dispenser pan, includes a weighted ball secured to a trip arm of the crash valve by a lanyard. The actuator will respond to the presence of gasoline or water by dislodging the ball and cause the ball to drop. The weight of the falling ball, translated through the lanyard, will cause the trip arm to close the crash valve and prevent further flow of gasoline therethrough and preclude the dispensing unit from pumping gasoline until the trip arm is reset.

Abstract: An automatically actuated regulation system for a natural gas pipeline having flow control unit, a vibration sensor, a gas flow meter, a trigger unit, and a microprocessor. The microprocessor actuates the flow control unit when two conditions are met. First, there must be a vibration which surpasses a predetermined threshold. Second, flow in the natural gas pipeline must have increased over the flow rate before the vibration. The system can be configured to store gas usage data and, in one embodiment, transmit the data to another location through the use of a modem or other communication means.

Abstract: System for the venting of a liquid tank, comprising a float valve, arranged in the tank, in communication with a pipe forming one end of a venting circuit, and a closed volume internal to the tank and provided with an emptying device, the closed volume functioning as a capacity intended for collecting any possible entrainments of liquid coming from the tank, the valve being located outside the volume of the capacity and being connected to the latter by means of the pipe of the venting circuit.

Abstract: In a vehicle, a housing has a weight that is normally centered by springs that yield to impact force components in several directions. This movement of the weight causes closing of fuel valves and opening of electrical switches that reduce the likelihood of fire or explosion in an accident.

Abstract: A roll over valve adapted for use in an evaporative gas control device for vehicles to simplify the structure thereof and to enable an accurate fuel fill-up, the roll over valve comprising: a hollow housing fixed at an upper end of a fuel tank and formed with a service pipe in order to cut off fuel gas; an outlet pipe fixedly disposed on the housing for connection to the housing and for connection again to a canister; a ball case for being liftably mounted in the housing for fuel and gas to pass therethrough and for being disposed with the outlet pipe arranged therethrough; a circular moving part for being formed at a bottom surface of the ball case to hold a ball therein; a sealing pad disposed on the moving part to shield the outlet pipe when the ball case is lifted; and a tensile spring provided between the ball case and the housing to apply an upward resilience to the ball case.

Abstract: A water saving mechanism is assembled with a shower device and is simply constructed in such a manner that supply of water is executed by the pressing of a push member and discharge of water is cut by the inclination of a shower head in a downward direction.

Abstract: Safety valve for venting a liquid tank, comprising means for ventilating the tank, including when the latter is inclined, for preventing liquid from being ejected if the tank is inclined or if waves of liquid are produced, for automatically closing in the event of inversion, for adjusting the useful volume and for allowing gas to escape during filling. As a preference, it also comprises means for ventilating it in the event of a depression or overpressure. The valve is characterized in that a flexible seal equips the seat of a valve element. As a preference, the head of the valve also comprises means for preventing dirt from getting into the tank. The valve is well suited to fuel tanks for diesel-engine motor cars.

Abstract: A vent valve assembly with roll over shut-off capability includes a housing, a vent valve that opens to allow vapor to escape from the tank in response to tank vapor pressure greater than a predetermined positive pressure and that opens to allow air or vapor entrance to the tank in response to tank vapor pressure below a predetermined negative pressure. A roll over valve is provided to open and close the fluid flow path between the vent valve and the tank interior, and a rocker arm assembly is rotatably mounted to the housing for positioning the roll over valve in the open position when the tanker is upright and for moving the roll over valve to the closed position when the tanker rolls more than a predetermined angle relative to the upright position. Stored liquid rising above the shut-off valve applies a further force closing the shut-off valve in relation to the head pressure.

Abstract: A seismic safety valve has a housing with a fluid inlet, a fluid outlet and a fluid passageway interconnecting the inlet and outlet. A recess is formed inside the housing along the fluid passageway, with a valve seat located adjacent to and below the recess. A valve member, made of a magnetic material, is in the fluid passageway and movable between a first position in the recess and a second position on the valve seat. The valve member closes the fluid passageway in the second position and opens the fluid passageway in the first position. The recess supports the valve member so that the valve member is movable from the recess upon the housing being subjected to a predetermined amount of seismic activity under forces generated by the predetermined amount of seismic activity and gravity. At least one electromagnet is on the housing outside of the fluid passageway.

Abstract: A resettable earthquake valve for gas lines, the valve having a housing with an external turn cock and an internal valve sleeve with a port that functions as a stopcock valve, the housing having an internal passage with a port and a closure biased valve disk displaceable from the port by a support member having an inertial mass, the support member being debilitated by a shock to the valve, the support member being connected to the biased valve disk at one end and engageable by a displaceable support base at the other, the valve having a cam mechanism for resetting the support member after being debilitated, for returning the support member to its support position displacing the valve disk from the valve port on resetting the valve.

Abstract: An automatically actuated regulation system for a natural gas pipeline having flow control unit, a vibration sensor, a gas flow meter, a trigger unit, and a microprocessor. The microprocessor actuates the flow control unit when two conditions are met. First, there must be a vibration which surpasses a predetermined threshold. Second, flow in the natural gas pipeline must have increased over the flow rate before the vibration.

Abstract: A gas-pressure relief valve unit, particularly for fuel vapours, comprising a body defining a chamber which communicates with first and second environments upstream and downstream of the unit respectively, through first and second apertures. The body is provided with a first and a second assemblies, the first assembly including a valve seat interposed between the apertures and an obturator urged by a resilient thrust element and movable between a position of engagement with the seat and a position spaced from it. The obturator can move away from the valve seat, overcoming the action of the resilient element, when a predetermined threshold value of the pressure differential between the environments is reached. When the obturator is engaged with the seat and the pressure differential between the environments is less than the predetermined threshold value, the valve means define a narrow passage which allows a small, continuous flow of gas between the first and second environments.