Pressure regulator with shutoff mechanism

A pressure regulator including a body having a body inlet, a body outlet and a fluid passageway defined therebetween for allowing a fluid to be dispensed therethrough, the body further including a pressure control chamber adapted to receive a control fluid at a control pressure; a valve disposed in the fluid passageway for restricting flow of the fluid through the fluid passageway; a regulating member operatively connected to the valve for adjusting the position of the valve so as to maintain the fluid in the fluid passageway at a nominal pressure; a pressure sensor disposed between the control chamber and the fluid passageway for sensing a difference between the nominal pressure and the control pressure; and a resilient shutoff member operatively connected to the valve and the pressure sensor for closing the valve when the difference between the nominal pressure and the control pressure is below a predetermined threshold value.

TECHNICAL FIELD

The invention relates to pressure regulators, and more specifically to pressure regulators with shutoff mechanisms.

BACKGROUND

Pressure regulators are used to control the pressure of a fluid, usually gas, being dispensed from a fluid source. Pressure regulators are typically used when the fluid is dispensed from the fluid source at a relatively high pressure which needs to be reduced for the fluid to be usable in machines or appliances. For example, propane is usually stored in propane cylinders at a relatively high pressure and is dispensed through a pressure regulator to a cooking apparatus such as a barbecue grill at a relatively low pressure.

A pressure regulator typically comprises a flexible membrane (or diaphragm) operatively connected to a valve adapted to restrict the flow of fluid in a conduit. The diaphragm senses the pressure of the fluid inside the pressure regulator and adjusts the position of the valve such that the pressure of the fluid dispensed from the pressure regulator is maintained at a desired pressure.

Unfortunately, most pressure regulators do not comprise any safety shutoff mechanism to prevent the fluid from being dispensed in case of a leak. A leak in the pressure regulator or in the gas line downstream of the regulator would not disturb the operation of the pressure regulator, which would continue to dispense fluid that would leak out in the environment. This may be both dangerous to the user and damaging for the environment. There is therefore a need for a new pressure regulator which would address at least one of the above-identified drawbacks.

SUMMARY

According to one aspect, there is provided a pressure regulator comprising: a body having a body inlet, a body outlet and a fluid passageway defined therebetween for allowing a fluid to be dispensed therethrough, the body further comprising a pressure control chamber adapted to receive a control fluid at a control pressure; a valve disposed in the fluid passageway for restricting flow of the fluid through the fluid passageway; a regulating member operatively connected to the valve for adjusting the position of the valve so as to maintain the fluid in the fluid passageway at a nominal pressure; a pressure sensor disposed between the control chamber and the fluid passageway for sensing a difference between the nominal pressure and the control pressure; and a resilient shutoff member operatively connected to the valve and to the pressure sensor for closing the valve when the difference between the nominal pressure and the control pressure is below a predetermined threshold value.

In one embodiment, the control pressure is higher than the nominal pressure. In one embodiment, the control pressure is lower than the nominal pressure.

In one embodiment, the pressure regulator further comprises a dispensing conduit having a first end coupled to the body outlet and a second end. In one embodiment, the dispensing conduit comprises an inner sidewall defining a main passageway and an outer sidewall outwardly spaced from the inner sidewall to define an interstitial space therebetween, the main passageway being in fluid communication with the fluid passageway and the interstitial space being in fluid communication with the pressure control chamber.

In one embodiment, the valve comprises a movable valve member and a seat for receiving the movable valve member. In one embodiment, the movable valve member comprises an arm pivotably mounted to the body. In one embodiment, the arm comprises a first end adapted to close the outlet and a second end operatively connected to the resilient shutoff member and the regulating member.

In one embodiment, the regulating shutoff member further comprises a linking member having a first end connected to the regulating member and a second end connected to the arm, the resilient shutoff member extending between the body and the linking member for moving the linking member relative to the body. In one embodiment, the linking member comprises a lower end operatively connected to the resilient shutoff member and an upper end, the linking member extending through the regulating member. In one embodiment, the linking member further comprises an opening located near its lower end for receiving the second end of the arm. In one embodiment, the arm is unattached to the linking member and further wherein the opening is wider than the second end of the arm to allow the arm to pivot within the opening when the linking member moves towards and away from the resilient shutoff member.

In one embodiment, the regulating member comprises a flexible regulating membrane extending adjacent to the fluid passageway and a resilient regulating member operatively connected to the flexible regulating membrane, the flexible regulating membrane being operatively connected to the movable valve member such that movement of the flexible regulating membrane moves the movable valve member, the resilient regulation member being adapted for counteracting the nominal pressure to limit movement of the flexible regulating membrane such that the movable valve member is moved to a position corresponding to the nominal pressure. In one embodiment, the resilient regulating member is adjustable to allow the nominal pressure to be adjusted. In one embodiment, the pressure sensor comprises a flexible shutoff membrane extending between the control chamber and the fluid passageway, the flexible shutoff membrane being adapted to move when the difference between the nominal pressure and the control pressure changes, the flexible shutoff membrane being operatively connected to the movable valve member.

In one embodiment, the nominal pressure is about 2.758 kPag. In one embodiment, the control pressure is greater than 3.447 kPag. In one embodiment, at least of a portion of the pressure control chamber is adjacent to at least a portion of the fluid passageway. In one embodiment, the resilient shutoff member is a helical spring.

DETAILED DESCRIPTION

Referring toFIG. 1, there is provided a pressure regulator100, in accordance with one embodiment. The pressure regulator100comprises a hollow body102which has a body inlet104, a body outlet106and a fluid passageway108defined between the body inlet104and the body outlet106. The fluid passageway108allows a fluid entering the body102through the body inlet104to be dispensed from the body outlet106.

In one embodiment, the fluid comprises a gas, such as propane gas. Alternatively, the fluid could instead comprise a liquid, such as water, or any other fluid considered by a skilled person to be suitable for use with the present pressure regulator.

Still referring toFIG. 1, the pressure regulator100further comprises a pressure control chamber110. Specifically, the pressure control chamber110is defined in the body102by a flexible shutoff membrane112. The pressure control chamber110is adapted to receive a control fluid at a control pressure, as will be further explained below.

Still referring toFIG. 1, the pressure regulator100is adapted to regulate the pressure of the fluid dispensed through the body outlet106. Specifically, the pressure regulator100further comprises a valve114disposed in the fluid passageway108. The valve114is adapted to restrict the flow of fluid through the fluid passageway108. It will be appreciated that by controlling the flow of fluid through the fluid passageway108, the pressure of the fluid dispensed through the body outlet106may also be controlled. In the illustrated embodiment, the position of the valve114is controlled by a regulating member116which is operatively connected to the valve114via a linking member117. Specifically, the regulating member116comprises a flexible regulating membrane118which is disposed adjacent the fluid passageway108. The regulating member116further comprises a resilient regulating member120extending between the regulating membrane118and the shutoff membrane112. In the illustrated embodiment, the resilient regulating member120comprises a helical spring. Alternatively, the resilient regulating member120could comprise any other type of resilient elements known to the skilled addressee.

When the pressure of the fluid builds inside the fluid passageway, the fluid exerts a force on the regulating membrane118, which is urged towards the resilient regulating member120. The regulating membrane118is operatively connected to the valve114and moves the valve114such that it increasingly restricts fluid flow as the regulating membrane118moves towards the resilient regulating member120, thereby lowering the pressure of the fluid within the fluid passageway as will be appreciated by the skilled addressee.

As the regulating membrane118moves towards the resilient regulating member120, the resilient regulating member120is further compressed and exerts an increasing force on the regulating membrane118. Since the force exerted by the regulating membrane118is decreasing as the valve114is increasingly restricting fluid flow through the fluid passageway108, the regulating membrane118will be urged away from the resilient regulating member120, which will tend to decrease the restriction of fluid flow through the fluid passageway108by the valve114.

In this configuration, the system defined by the valve114, the regulating membrane118and the resilient regulating member120will therefore tend towards a state in which an equilibrium is formed and maintained between the force exerted by the resilient regulating member120and the force exerted on the regulating membrane118by the fluid in the fluid passageway108. In this state, the fluid in the fluid passageway108is at a nominal pressure. It will be appreciated that it is possible to select a suitable resilient member, membrane and valve to obtain a desired nominal pressure. It will also be appreciated that it could be possible to adjust the selected resilient member, membrane and valve to modify the nominal pressure.

Still referring toFIG. 1, the pressure regulator100further comprises a pressure sensor122adapted to sense a pressure difference between the nominal pressure of the fluid in the fluid passageway108and the control pressure of the control fluid in the pressure control chamber110. In the illustrated embodiment, the pressure sensor122is defined by the shutoff membrane112. Specifically, the control pressure of the control fluid in the pressure control chamber110exerts a force on the shutoff membrane112, which is urged away from the pressure control chamber110.

The pressure regulator100further comprises a resilient shutoff member124operatively connected to both the valve114and the pressure sensor122. Specifically, the resilient shutoff member124abuts the linking member117which is connected to the regulating membrane118, and the resilient regulating member120is disposed between and abuts both the regulating membrane118and the shutoff membrane112.

In the embodiment illustrated inFIG. 1, the control pressure of the control fluid is higher than the nominal pressure when the pressure regulator100is in a normal operating mode. In this configuration, the shutoff membrane112is convex towards the resilient shutoff member124, as shown inFIG. 1. The resilient shutoff member124is therefore compressed by the force exerted by the control fluid on the shutoff membrane112. As it is compressed, the resilient shutoff member124exerts a force in a direction opposite the force exerted by the control fluid. In this configuration, the force exerted by the resilient shutoff member124on the shutoff membrane112counteracts the force exerted by the control fluid on the shutoff membrane112and the system is at equilibrium.

Referring now toFIG. 3, if the control pressure of the control fluid decreases, the difference between the control pressure and the nominal pressure also decreases. When the difference between the control pressure and the nominal pressure decreases such that it is below a predetermined threshold value, the force exerted by the control fluid on the shutoff membrane112decreases and the resilient shutoff member124moves the entire regulating member116, including the linking member117, the regulating membrane118and the resilient regulating member120, towards the pressure control chamber110. Since the linking member117is operatively connected to the valve114, this movement allows the resilient shutoff member124to close the valve114to thereby completely restrict the flow of fluid through the fluid passageway108, effectively placing the pressure regulator100in a shutoff mode.

As shown inFIG. 3, a decrease in the control pressure also moves the shutoff membrane112upwardly. This causes the resilient regulating member120, which is connected to the shutoff membrane112, to be extended, and thereby also exerts a pulling force on the valve114which contributes to moving and maintaining the valve114closed.

It will be appreciated that in the embodiment illustrated inFIGS. 1 to 3, the control pressure of the control fluid could decrease in the event of a leak from the pressure control chamber110. The leak could comprise a leak from the pressure control chamber110to an exterior environment in which the pressure regulator100is used. The leak could also comprise a leak from the pressure control chamber110into the fluid passageway108. In the illustrated embodiment, the pressure regulator100further comprises a dispensing conduit126having a first end127adapted to be connected to the body102and a second end129adapted to be connected to a machine, appliance or circuit to which the fluid is to be dispensed at the nominal pressure.

In one embodiment, the machine, appliance or circuit comprises a barbecue grill. In an embodiment in which the fluid comprises water, the machine, appliance or circuit could instead comprise a water distribution circuit. Alternatively, the machine, appliance or circuit may comprise any machine, appliance or circuit that a skilled person would consider appropriate to be used with the pressure regulator100.

In the illustrated embodiment, the dispensing conduit126comprises an inner sidewall128which defines a main dispensing passageway130and an outer sidewall132which is outwardly spaced from the inner sidewall128to define an interstitial space134between the inner sidewall128and the outer sidewall132. The main dispensing passageway130is in fluid communication with the fluid passageway108of the body102and the interstitial space134is in fluid communication with the pressure control chamber110, as will be further explained below. In this configuration, the interstitial space134therefore defines an extension of the pressure control chamber110while the main dispensing passageway130defines an extension of the fluid passageway108of the body102. Since the main dispensing passageway130is only separated from the interstitial space134by the inner sidewall128, the pressure control chamber110is therefore adjacent to the fluid passageway108.

As explained above, the control pressure is higher than the nominal pressure in the embodiment illustrated inFIGS. 1 to 3. In this configuration, a leak through the inner sidewall128would cause the control pressure to decrease such that the difference between the control pressure and the nominal pressure becomes lower than the predetermined threshold value. The control pressure may also be higher than an exterior environment pressure, and a leak through the outer sidewall132to the exterior of the pressure regulator100would therefore also cause the control pressure to drop such that the difference between the control pressure and the nominal pressure becomes lower than the predetermined threshold value. Alternatively, the pressure control chamber110may not be adjacent to the fluid passageway and the valve114may only be closed by the resilient shutoff member124when a leak is formed through the outer sidewall132.

In one embodiment, the difference between the control pressure and the nominal pressure in a normal operating mode could be substantially equal to the predetermined threshold pressure. In other words, the slightest drop in pressure from the initial control pressure would signal a leak and the valve114would immediately be closed. In another embodiment, the predetermined threshold value is below the initial difference between the control pressure and the nominal pressure, such that a loss of a certain amount of control fluid is allowed before the valve114is closed by the resilient shutoff member124.

Now referring toFIG. 2, the body102comprises a lower body portion200, an upper body portion202and an intermediate body portion204located between the lower and upper body portions200,202. The lower, upper and intermediate body portions200,202,204are assembled together using assembly techniques known to the skilled addressee such as fastening, welding or the like.

In the illustrated embodiment, the regulating membrane118is clamped between the lower body portion200and the intermediate body portion204, and the shutoff membrane112is clamped between the intermediate body portion204and the upper body portion202. Specifically, the regulating membrane118comprises a peripheral frame205which is sized and shaped to be received in a corresponding peripheral recess207of the lower body portion200. The peripheral recess207is covered by the intermediate body portion204when the intermediate body portion204is assembled with the lower body portion200such that the regulating membrane118can no longer be removed from the peripheral recess207.

In one embodiment, the regulating membrane118and the peripheral frame205are circular. Alternatively, the regulating membrane118and the peripheral frame205could have any other shape considered by the skilled addressee to be appropriate for use with the pressure regulator100. Similarly, the shutoff membrane112comprises a peripheral frame209which is sized and shaped to be received in a corresponding peripheral recess211of the upper body portion202. The peripheral recess211is covered by the intermediate body portion204when the intermediate body portion204is assembled with the upper body portion202such that the shutoff membrane112can no longer be removed from the peripheral recess211.

In one embodiment, the shutoff membrane112and the peripheral frame209are circular. Alternatively, the shutoff membrane112and the peripheral frame209could have any other shape considered by the skilled addressee to be appropriate for use with the pressure regulator100.

In the illustrated embodiment, the body inlet104, the body outlet106and the fluid passageway108are defined in the lower body portion200. Specifically, the body inlet104comprises a tubular projection206which extends away from the lower body portion200and an inlet bore208extending from the tubular projection206inwardly into the lower body portion200. The inlet bore208is sized and shaped to receive a corresponding outlet connector from a fluid source, such as a propane cylinder. Still in the illustrated embodiment, the body outlet106comprises a cylindrical outlet nipple210extending away from the lower body portion110and an outlet bore212extending from the outlet nipple210inwardly into the lower body portion200.

In one embodiment, the outlet nipple210is sized and shaped to receive the first end127of the dispensing conduit126. Specifically, the outlet nipple210may comprise a plurality of hose barbs214which are adapted to engage the outer sidewall132of the dispensing conduit126. In the illustrated embodiment, the inner sidewall128extends into the outlet bore212and a tubular sealing insert216sealingly connects the main dispensing passageway130of the dispensing conduit126to the fluid passageway108.

In the embodiment illustrated inFIG. 2, the body inlet104defines an inlet axis A1and the body outlet106defines an outlet axis A2which is orthogonal to the inlet axis A1. Alternatively, the body inlet104and the body outlet106could instead be located on opposite sides of the body102such that the inlet axis A1and the outlet axis A2are parallel to each other.

Still referring toFIG. 2, the fluid passageway108comprises a lower body chamber218which is in fluid communication with both the inlet bore208and the outlet bore212. In the illustrated embodiment, the lower body chamber218houses the valve114and the resilient shutoff member124.

More specifically, the resilient shutoff member124is received in a recess220defined in the lower body portion200, inside the lower body chamber218. In the illustrated embodiment, the resilient shutoff member124comprises a helical spring. Alternatively, the resilient shutoff member124could comprise any other type of resilient elements known to the skilled addressee.

In the illustrated embodiment, the valve114comprises a movable valve member222and a seat224for receiving the movable valve member222. More specifically, the movable valve member222comprises an arm226pivotably mounted to the body102via a pivot shaft228. The arm226comprises a first arm end230located towards the resilient shutoff member124and a second arm end232located near the seat224. The second arm end232is adapted for abutting the seat224and form a seal therewith to thereby close the valve114.

Still in the illustrated embodiment, the pivot shaft228is located closer to the second arm end232than to the first arm end230. It will be appreciated that this allows the arm226, acting as a lever, to exert a relatively greater force on the seat224in order to provide a relatively tight seal when the valve114is closed. In the illustrated embodiment, the arm226further comprises an elastomeric pad234secured to the second arm end232to further provide a relatively tight seal when the valve114is closed.

Still referring toFIG. 2, the seat224comprises a generally conical head236and an elongated body238extending away from the conical head236. The seat224further comprises a central bore240and is mounted through the lower body portion200to allow fluid communication between the inlet bore208and the lower body chamber218.

In the illustrated embodiment, the linking member117extends through the regulating membrane118and comprises a lower end242operatively connected to the resilient shutoff member124and an upper end244located within the intermediate body portion204. The linking member117further comprises an opening246located near its lower end242for receiving the first arm end230of the arm226. Specifically, the first arm end230is simply inserted in the opening246and is unattached to the linking member117. In the illustrated embodiment, the opening246is wider than the first arm end230to allow the arm226to pivot within the opening246when the linking member117moves towards and away from the resilient shutoff member124.

Still referring toFIG. 2, the intermediate body portion204defines an intermediate body chamber248which houses the resilient regulating member120. The intermediate body chamber248is in fluid communication with the environment via a vent250extending through the intermediate body portion204. The pressure inside the intermediate body chamber248is therefore the same as the exterior environment pressure.

The resilient regulating member120extends between the regulating membrane118and the shutoff membrane112. In the illustrated embodiment, a first spreader disc252is further provided on the regulating membrane118to receive the resilient regulating member120and spread the force exerted by the resilient regulating member120evenly on the regulating membrane118. Similarly, a second spreader disc254is also provided on the shutoff membrane112to receive the resilient regulating member120and spread the force exerted by the resilient regulating member120evenly on the shutoff membrane112.

Each spreader disc252,254may be secured to its respective membrane118,112. Alternatively, the spreader discs252,254may instead be secured to the resilient regulating member120. In yet another embodiment, the spreader discs252,254are not secured to the membranes118,112or to the resilient regulating member120.

In the illustrated embodiment, the intermediate body chamber248further houses a relief spring256disposed around the linking member117. The relief spring256is further prevented from moving away from the linking member117by a retainer ring258secured to the linking member117. The relief spring256is adjusted such that if the pressure of the fluid inside the fluid passageway108exceeds a predetermined upper limit, the pressure from the fluid will exert a force on the regulating membrane118and will push the regulating membrane118and the linking member117away from the fluid passageway108until the linking member117can no longer move. The fluid will then continue to exert a force on the regulating membrane118and compress the relief spring256until it is moved sufficiently relative to the linking member117such that a gap is created between the regulating membrane118and the linking member117, by which the fluid may flow into the intermediate body chamber248and be vented to the exterior environment through the vent250.

Still in the illustrated embodiment, a plug screw260and a corresponding plug nut262engage the shutoff membrane112in order to seal a hole at the center of the shutoff membrane112. Alternatively, the plug screw260and the plug nut262are not provided and the shutoff membrane112is continuous (i.e. the shutoff membrane112does not comprise a central hole).

Still referring toFIG. 2, a pressure control channel264is further defined in the body102. Specifically, the pressure control channel264extends between the pressure control chamber110and the outlet bore212and is adapted to be in fluid communication with the interstitial space134of the dispensing conduit126.

In the illustrated embodiment, a filling valve266, for example a poppet valve, is further mounted in the body102, in fluid communication with the pressure control channel264and/or the pressure control chamber110to allow the control fluid to be dispensed within the pressure control chamber110until the control pressure is obtained. Alternatively, the pressure regulator100does not comprise a filling valve266and is instead pressurized and then sealed with the control fluid at the desired control pressure.

It will be understood that in the embodiment described above, the control pressure is greater than the exterior environment pressure, and may also be greater than the nominal pressure. For example, the nominal pressure could be about 0.4 psig (psi gauge) or about 2.758 kPag (kPa gauge) and the control pressure could be above about 0.5 psig or about 3.447 kPag.

Alternatively, the control pressure could instead be lower than the exterior pressure and the nominal pressure. For example, the resilient shutoff member124could instead be extended when the pressure regulator100is in normal operating mode, and pull the linking member117to thereby close the valve114when the control pressure increases such that the difference between the control pressure and the nominal pressure decreases below the predetermined threshold value. Alternatively, the resilient shutoff member124could instead be located inside the pressure control chamber110to move the shutoff membrane112away from the pressure control chamber110when the control pressure rises above the predetermined threshold value, thereby closing the valve114.

The pressure regulator100therefore constitutes a simple and efficient way to provide pressure regulation of a fluid with a shutoff feature which is activated when a leak of fluid is detected, which may help prevent loss of fluid which could be costly, wasteful, damaging to the environment and potentially harmful. Furthermore, the pressure regulator100is relatively simple and eliminates the need for multiple valves by having the fluid regulation and the shutoff function performed by the same valve.