JPH1054470A - Gas leak sensing cutoff valve provided with reset protective unit, and detachable pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leak sensing valve for immediately shutting off gas supply after detecting gas leakage. SOLUTION: A gas leak sensing valve is directly arranged in a gas supplying line to a plurality of units or a branch line to a single unit. A valve body is so arranged as to be approximately perpendicularly erected. Gas is allowed to flow into a pipe coupling nipple 26 through the passage and allowed to a downstream unit from a discharging passage. A valve assembly is normally translated toward the lower end of a valve chamber by its own weight, and the gas flow is not shut. When gas leak is generated downstream from a gas leak sensor, surge is generated in the gas flow passing the valve. The increased flow rate exceeds the flow rate capacity limit of the passage, the net differential pressure is generated in the valve assembly, the differential pressure energizes the valve assembly to the terminal side, drives a gasket 46 of the valve assembly, and brings it in contact with a step part of the valve chamber 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a gas flow control valve, and more particularly, to a gas flow control valve installed in a gas supply line.
The present invention relates to a gas valve for stopping a gas flow when a leak occurs in a gas supply line.

[0002]

BACKGROUND OF THE INVENTION Gas fuel appliances using fuels such as methane, butane, propane, or combinations thereof, are widely used throughout the world. Although such devices and the systems for fueling them are highly developed and carefully designed, the risk of catastrophic failure is small but substantial. Gas leaks in equipment or supply lines can and do cause fatal fires and explosions each year. Many of these accidents can be prevented by better caution and vigilance, and accidents caused by other mechanical failures, broken supply lines, etc. can be prevented by the use of gas leak sensing shut-off valves. . However, gas leak sensing shut-off valves have not been widely used.

In densely populated regions of the world, geological fault lines are known, and it is recognized that in places where earthquakes frequently occur, gas supply lines are extremely susceptible to damage by ground vibration and displacement. Also, the main destructive effect of many earthquakes is a fire storm caused by a large supply of fuel leaking from damaged gas pipes and a lack of water supply to extinguish the associated fire. Again, gas leak sensing shutoff valves can reduce the risk of this catastrophe, but such valves are not widely used. Earthquake sensing valves, which shut off gas flow in response to an earthquake, have been installed in some buildings but have not been used successfully in general. An earthquake can trigger a valve to shut off gas flow even though the gas system is intact and intact. As a result, the gas system is shut down and rendered inoperative without good cause. Furthermore, shock waves, vibrations caused by extremely heavy vehicles passing nearby, and the like can also trigger the seismic sensing valve. Thereafter, all test ignitions must be performed again and the associated pilot valve must be reset. Many homeowners and building occupants are not able to perform these tasks themselves, and must pay professionals for this.

[0004]

SUMMARY OF THE INVENTION Seismic sensing valves tend to be expensive due to their design complexity, and their cost is a hindrance to their widespread use. In addition, seismic sensing valves are generally mounted on the walls of buildings and dwellings to be protected and must be accurately leveled for the valves to be effective. The gas tubing must then be plumbed through the valve, and additional tubing and fittings and wall mounting, leveling, and tubing assembly add significant cost. Given the problem of false triggering and the high cost, it is not surprising that seismic sensing valves are not widely used.

Gas leak sensing valves are known in the prior art, for example, as described in Israel Patent 96312, issued to the present inventor. Such a device is effective in distinguishing between a small gas flow for appliance use and a large gas flow due to leakage in a gas supply system or gas fuel appliance. The more convenient, effective and inexpensive such devices are, the more widely they can be used.

[0006]

SUMMARY OF THE INVENTION The present invention generally comprises an improved gas leak sensing valve for detecting gas leaks from a building gas supply or gas line to a gas fuel appliance and immediately shutting off the gas supply. Become. Thus, this valve accurately distinguishes between a normal gas flow and an abnormally high gas flow due to leakage. This valve is very simple in construction and can be manufactured and installed inexpensively. In addition, the valve is designed to be installed directly into existing gas piping with minimal effort and materials, and the total cost of purchase and installation is sufficient to be a positive factor in widespread use. It is cheap.

The gas leak sensing valve includes a substantially cylindrical body having an inlet having an internal thread at one end. A fitting nipple is mounted within the inlet by an O-ring seal and includes a male threaded end adapted to be mounted to a gas supply tube or the like. An inner bore extends into the valve body and is substantially coaxially connected to the inlet. The fitting nipple has a pair of slots opposing each other along a diameter formed in the end face.

A stepped chamber is defined in the middle of the hole. A valve element assembly is provided in the valve chamber for translational movement in the axial direction of the bore. The valve element assembly includes a cup-shaped member having a cylindrical side wall closed at one end and a pair of diametrically opposed openings extending along the side wall. A flexible gasket is secured to the closed end of the valve element, the periphery of the gasket extending radially outward from the valve element side wall.

The cylindrical side wall is dimensioned to be received in the narrow portion of the stepped valve chamber with minimal clearance to allow for axial translation. The outer edge of the gasket has a diameter sufficient to hermetically abut the annular shoulder of the narrow portion of the valve element. The cylindrical side wall of the valve element generally extends partially into the narrow portion of the valve chamber and passes from the fitting nipple through opposing slots along the diameter of the inner end of the fitting nipple to provide a seal gasket and an annular step. A flow path is formed through the gap and through the opposing openings along the diameter of the cylindrical side wall to the end of the bore.

A discharge passage extends diametrically within the valve body and is connected to the end of the bore for fluid passage. The discharge passage extends through a neck extending radially from the valve body, and a coupling having an internal thread is rotatably mounted on the neck. An access port may be provided in the valve body so as to face the discharge path along the diameter.

At the distal end of the valve body is mounted a reset mechanism comprising a spindle provided for translational movement at the distal end of the bore and a pin extending from the spindle into the valve chamber. A compression spring is provided around the spindle,
A second O-ring seal is mounted on the spindle to bias the reset mechanism for distal translation and to prevent gas flow over the spindle. The exterior of the spindle has a button-like end that extends upward from the top of the valve. A reset button protector extends from the top of the valve. It consists of a cylindrical side wall extending coaxially around the button end projecting outside the spindle. The cylindrical side wall projects from the valve body the same distance as the outer part of the button end, thereby accidentally resetting or releasing the valve against its function and purpose by hitting the button and pressing the button The button is protected from any falling objects that might keep it in a locked condition.

[0012] The reset valve protector can be configured as a sleeve provided around the reset button. The sleeve has a threaded proximal end which is adapted to engage a neck extending from the valve body coaxially with the button end with a corresponding thread. The inner surface of the sleeve is close to the reset button to prevent dust from interfering with the push button operation.

The gas leak sensing valve is installed directly in a gas supply line to multiple instruments or a branch line to a single instrument. The axis of the cylindrical valve body is ± 3 with respect to the vertical direction.
It is arranged almost upright so as to be 0 °. The gas flows into the fitting nipple through the above-mentioned flow path and flows out of the discharge path to the downstream instrument. In normal operation, the valve assembly translates under its own weight toward the lower end (inlet) of the valve chamber and the gas flow is not blocked. However, if a gas leak occurs downstream of the gas leak sensor, a surge will occur in the gas flow passing through the valve. The increased flow rate exceeds the flow capacity limit of the flow path, creating a net pressure differential in the valve assembly. The pressure differential biases the valve assembly distally and drives the gasket of the valve assembly to abut the valve chamber shoulder. The effective volume of the flow path is selected such that the valve is sensitive to flow rates only slightly higher than the consumption rate of the gas appliances (such as) downstream of the valve. Thus, a very small percentage of leaks that would cause gas accumulation and explosive conditions in the enclosed space are also prevented.

In order to reset the valve and return to normal operating conditions, it is generally necessary to manually push the button end of the spindle. The button can only be pressed with a thin object having a diameter smaller than the inner diameter of the reset protection sleeve. Therefore, accidental resetting of the valve by accidental contact of falling objects is prevented. The spindle translates against the elastic biasing force of the compression spring, the pin translates toward the base and abuts the valve assembly,
The valve assembly is biased toward the base to re-open the flow path. When the button end is released, a spring drives the spindle towards the end and the valve is again positioned to allow normal gas flow and detect any significant gas leaks.

In another aspect, the present invention is directed to a gas leak sensing valve whose external construction and dimensions are selected so that the valve can be inserted into a typical gas supply line with minimal additional parts and installation effort. Become. The gas supply line from the gas mains is usually connected to the mains supply line (in series), a manual supply shut-off valve, a pressure controller, a gas usage meter, a vertical conduit from the meter, a T to connect to the vertical conduit. And a delivery tube extending from the T-shaped fitting to the consumer premises. T
One opening of the mold fitting is plugged and, very rarely, used to access equipment on the consumer side and perform a gas pressure test downstream of a meter on the consumer premises.

The gas leak sensing valve of the present invention is designed to replace the T-joint of a standard gas line facility both spatially and functionally. The standard T-type fitting or vertical conduit extending from the gas meter can be removed and the valve of the present invention can be placed directly instead. The swivel fitting at the discharge end of the valve is important to enable this direct replacement. This simplicity of installation minimizes installation costs, requires little or no additional components, and requires only a few minutes of labor. The plugged opening opposite the outlet of the valve acts as the plugged opening of a conventional T-fitting. Further, since the initial installation work is performed outside the building, there is no need to enter the occupied indoor space. Further, unlike conventional seismic sensing valves, the gas leak sensing valve of the present invention does not need to be installed on the building structure itself, but is inserted into the gas supply line piping, thereby supporting the valve.

In accordance with another aspect of the present invention, there is provided a removable fitting mounted between an outlet fitting of a gas leak sensing valve and a delivery pipe extending to a consumer premises. The detachable fitting is a designated weakness of the delivery network, and is initially broken or crushed in the event of an event such as an earthquake that separates the premises from the gas meter.
By placing the removable fittings adjacent to the gas leak sensing valve, any damage to the customer drainage network will occur as close as possible to the sensing valve where it is most easily detected. . It is also important to arrange the detachable pipe joint outside the building. Of course, damage to the gas delivery network downstream of the detachable fitting also triggers the sensing valve to shut off gas flow.

In a preferred embodiment, the detachable fitting includes a pair of female couplings each having an internal bore threaded at an outer end. A tubular member extends between the female couplings and includes a pair of radial flanges extending from opposite ends thereof. Each flange end of the tubular member is received and secured within the inner end of each female coupling. Each female coupling includes an O-ring seal that abuts the tubular member so as to form a rotatable sealed engagement between the female coupling and the tubular member.

A remarkable feature of the present invention is that an annular groove is provided in the middle of the tubular member. This groove is formed in the side wall forming the tubular member. The annular groove forms a thinner side wall that is weaker than the rest of the tubular member and is more susceptible to breakage, especially under shear loading. The depth of the groove determines the shear rupture strength of the tubular member and can be calculated or measured empirically.

A further important feature of the present invention is the provision of a compression coil spring received around the tubular member and abutting the ends of the female coupling. The spring provides an elastic restoring force that urges the coupling axially into the tubular member and against the flange end of the tubular member. This spring force is much weaker than the tensile strength of the tubular member. The presence of the spring does not affect the independent rotation of the coupling with respect to the tubular member. In fact, the assembly has all the functional attributes of a straight union.

It will be appreciated that the spring will act if the shear forces exerted on the tubular member are sufficient to cause breakage in the thin sidewall region of the annular groove. If the side wall breaks, two end-to-end lacking tensile integrity assemblies are formed. The spring restoring force acts to separate the two assemblies and create a significant gap between them. This gap consists of an open breach into the piping system where the removable fittings are installed,
Form a significant outflow of any pressurized fluid into the piping system.

The shear rupture strength of a tubular member can be designed to correspond to a particular centripetal acceleration on both ends of a detachable fitting, measured in units of gravity (inertial force), and can be measured by the Richter scale. It can also be expressed by a seismic intensity measurement such as In the event of an earthquake or other event that exerts a shear force on the pipe assembly, the detachable fitting breaks and disassembles at a specified shear failure strength threshold, allowing the valve to pass fluid through it. Creates a tear that triggers a break. Therefore, the gas leak sensing valve can effectively operate as an earthquake sensing or acceleration sensing shutoff valve.

[0023]

DETAILED DESCRIPTION OF THE INVENTION The present invention generally comprises an improved gas leak sensing valve for detecting gas leaks from a building gas supply or gas line to a gas fuel appliance and immediately shutting off the gas supply. As shown in FIGS. 1 and 2, gas leak sensing valve 11 comprises a generally cylindrical valve body 12 having a connection 13 with a male thread extending from its lower end and a reset mechanism 14 extending from its upper end. Having. A cylindrical neck 16 extends radially from the upper end of the body 12 and has a rotatable coupler 17 attached thereto. An optional access port 18 is provided diametrically opposite the neck 16 and is sealed by a threaded plug 19.

As shown in FIGS. 4-6, the valve body 12 includes an inner hole 21 extending coaxially therein. The bore 21 is provided with a step, thereby defining different portions including a proximal end 22 having an internally threaded portion, an intermediate valve chamber 23, and a narrow upper portion 24. Pipe fitting nipple 26
Is a male screw 2 which is engaged with the screw portion 22 of the inner hole 21.
8 is provided. The nipple 26 includes an O-ring seal 29 at the base of its thread 28 that can form a hermetic seal at the lower opening of the bore 21. A central hole 27 extends axially within the nipple 26 and an outer hexagon 31 is provided for engaging a standard wrench. Nipple 26
A pair of slots 32 arranged along the diameter at the inner end of
Is formed on the end face. As explained below, more slots 3 depending on the specified flow rate in valve 11
2 may be formed.

As shown in particular in FIGS. 4 and 5, the present invention further includes a valve element assembly 41. The valve assembly 41 comprises a cup-shaped member having a cylindrical side wall 42 and an end wall 43 closing them at one end. Openings 44 opposing each other along a pair of diameters are provided in the side wall 42 adjacent the end wall 43. Depending on the specified flow rate in the valve 11, more than two openings may be provided if necessary. A disk-shaped flexible gasket 46 is attached by an end assembly 45 to the valve element abutting the end wall 43, with the periphery of the gasket 46 extending radially outwardly over the side wall 42. The cylindrical side wall 42
It is dimensioned to be received in the stepped valve chamber 23 with minimal clearance for axial sliding and translation. The periphery of the gasket 46 is
Has a diameter sufficient to hermetically abut the annular step 47 defining End assembly 45 is dimensioned to be received within the inner end of bore 27 and gasket 46 can abut the end surface of fitting nipple 26. Thus, the valve element assembly can translate axially from a lower position where the gasket abuts the inner end of the fitting nipple 26 to an upper position where the gasket abuts the annular step 47.

The reset mechanism 14 has a neck portion 51 having a thread on the outside and extending axially from the cylindrical valve body 12 toward the distal end. A spindle 52 extends into the distal opening of the bore 21 with a minimum clearance for sliding translation. A pin 53 extends axially from the spindle 52 toward the base, the lower end of which extends into the cylindrical side wall of the valve element assembly 41. A threaded nut 54 holds the spindle 52 in the bore, and a second O-ring seal 56 is attached to the spindle 52 to prevent gas flow over the spindle 52. Spindle 52
A compression spring 57 is provided around the circumstance, and urges the reset mechanism 14 to translate toward the distal end. A button end 58 is provided outside the spindle 52 to facilitate manual engagement.

The present invention further includes a drain 61 extending diametrically within the valve body and connecting to the distal end of bore 21 for fluid passage. The discharge path 61 is the valve element 12
A tubular member 63 is mounted in the neck 62 and extends through a neck 62 that projects radially from the neck. A coupling nut 64 having a female thread is permanently attached to the member 63, and an O-ring seal 66 forms a sealed union between the nut 64 and the member 63.

As an optional mode, the access port 18 is arranged so that the valve body 1 is opposed to the discharge path 61 along the diameter.
2 is provided with an access hole 71 with a female thread.
A threaded plug 19 is mounted in the hole 71 to seal the access port 18, which can be opened for the following purposes.

The valve 11 is installed in series with the gas supply pipe, and FIG.
When arranged substantially vertically (± 30 °) as shown in FIG. 5, the valve element assembly 41 is disposed at the lower end of the valve chamber 23, and the gasket 46 abuts the inner end face of the fitting 26. As shown in FIG. 7, a gas flow path through the valve 11 is formed. This flow path extends from the hole 27 in the nipple 26 through the slot 32 along the diameter of the end of the nipple 26 into the valve chamber 23 and further through the hole 44 in the cylindrical side wall 42 into the cup-shaped valve element assembly. ing. Then the gas is in hole 2
1 and flows from the discharge channel 61 to the nut 64.
Spills into the pipe connected to. There is no particularly preferred angular arrangement or orientation between slot 32 and hole 44.

It will be appreciated that the effective cross-sectional area of the flow path through slot 32 and hole 44 is substantially smaller than the remaining flow path through valve 11. The effective cross-section (which can be determined empirically or obtained by dimensional calculations) determines a threshold flow rate below which the gas flow is not substantially restricted. This threshold flow rate is determined as the maximum expected gas draw of the installation at standard gas supply pressure. This is true whether the retraction amount consists of the rated consumption of a single gas appliance or if it consists of several appliances all over the premises. When the gas flow reaches the threshold flow rate, in a region where the cross-sectional area is restricted, the valve assembly floats above the gas flow against the dead weight of the valve assembly upwardly in the valve assembly toward the distal end. Is generated. Therefore, the relationship between the mass of the valve assembly and the effective cross-sectional area of the flow path is important in determining the flow rate of the system. This mass mainly depends on the side wall 42 and the end wall 4.
3, the effective cross-sectional area of the flow path is a function of the width of the slot 32 and the number and diameter of the holes 44 in the side walls 42.

When the gas flow exceeds the threshold flow rate, valve element 41 is biased upwardly into the valve chamber. Side wall 4
The second bore 44 is partially closed by an adjacent annular step 47, further limiting the flow capacity and increasing the pressure differential within the valve assembly. The valve element 41 is even more strongly urged upward, and this feedback effect causes the valve assembly 41 to be accelerated and lifted, and the gasket 46 to move the annular step 4
4 to a point where all flow through valve 11 is cut off (FIG. 8). The feedback effect ensures that the valve element is not locked in a position where it substantially restricts gas flow to the instrument downstream of valve 11. Valve assembly 4
The gas pressure below 1 maintains the shut-off condition.

To release the valve again to allow the gas flow to pass, push the button end 58 of the reset mechanism 14 by hand and bias the pin 53 against the end wall 43 of the valve element 41; This is driven downward in the valve chamber 23. When the button end 58 is released and the reset mechanism 14 is retracted,
The flow path shown in FIG. 7 is formed. However, if the leak (or other condition) that caused the valve to close is not suppressed, the valve will immediately reclose.

FIG. 16 is a cross-sectional view showing a modification of the valve 11, which includes another valve element assembly 41 '. The valve element assembly 41 'includes a parasol-shaped closure element 42', which has a vertical slot 4 in its head 46 '.
3 ′. The pin 53 is shorter than in FIG. 4 and is occupied by the closing element 42 'but the valve element 41'.
To accommodate the volume along the centerline of the hole 21 not occupied by the concave cup-shaped member. The gasket 44 'is closed by a conical disc 45'
It is fixed to the base of 2 '. The vertical slots 43 'function similarly to the holes 44 to restrict gas flow through the valve 11.
In FIG. 16, the valve element assembly 41 ′ is in the shut-off position, and the gasket 44 ′ abuts the step 47.

Another important feature of the gas leak sensing valve 11 is that it has an external structure and dimensions that can be easily installed in a typical gas supply line plumbing with a minimum of additional components and effort. It is in. As shown in FIG. 9, a typical prior art gas supply connection includes a vertical conduit 81 that extends upwardly from the ground and connects below to a gas mains. A manual shut-off valve 82 and a pressure regulator 83 are connected in series to the vertical conduit 81, the latter increasing the pressure from main pressure (typically tens of pounds per square inch) to consumer supply pressure (typically square inches). Per pound). A U-shaped tube 84 (or tube assembly) connects the pressure controller output to a meter 86 for measuring gas consumption. Measuring instrument 86
A short vertical conduit 87 extends from it and connects to a T-fitting 88. One end of the T-fitting 88 is connected to a pipe 89 that is the source of all gas consuming equipment on the consumer premises.
The other end 91 of the T-shaped fitting 88 is sealed with a threaded stopper so that it can be released when a gas pressure test is performed on the consumer side of the measuring meter 86. Because many gas companies specify standard dimensions and spacing for components, the components of FIG. 9 are often arranged as shown or similar.

As shown in FIG. 10, the gas sensing shut-off valve 11 of the present invention is constructed so as to be particularly connected between the gas meter 86 and the consumer supply pipe 89. That is, the installation of the valve 11 is performed by first setting the vertical pipe 87 and the T-shaped
And replace these two members directly with the valve 11. The screw end 13 is attached to a nut above the measuring instrument 86, and the screw end of the pipe 89 is attached to the rotary coupling 17 of the valve 11. This installation process requires only a few minutes of labor and minimal tools and materials. By constructing the valve economically and saving material and labor costs, the premises is maximally protected with minimal costs.

It will be appreciated that the plugged port 18 of the valve 11 provides the same access function as the port 91 of the replaced conventional T-fitting 88. The port 18 can be opened if necessary to measure the gas pressure flowing into the customer supply pipe 89, and the meter 86 and the pressure regulator 83 can be opened if necessary.
Can be adjusted.

According to another aspect of the present invention, the valve 11
Can be inserted between the outlet of the valve 11 and the customer supply pipe 89. The detachable nipple 92 may be formed of a short straight union having an annular groove 93 formed in a side wall. Grooves 93 extend into the tube sidewalls a sufficient distance to weaken the sidewalls and make them more susceptible to breaking by seismic vibrations and ground motion than other more robust sections of tube 89 and associated branches downstream of valve 11. . Therefore, in the event of damage to the premises due to an earthquake or ground motion, or a storm, tornado, flood or the like, the gas supply unit that is likely to be damaged first is the removable nipple 92. The failure will occur close to valve 11, where it is most easily detected. In addition, the break is located outside the premises and the premises is better protected from small gas leaks and gas accumulation. Of course,
Although less likely, damage can initially occur downstream of the removable nipple in the gas delivery network, which also triggers the sensing valve to shut off gas flow.

In another embodiment of the gas safety shut-off valve shown in FIGS. 11 and 12, a component having a structure and function similar to the components described above is indicated by a dash (').
It is referred to by the same reference number appended with. The gas safety shutoff valve 11 'comprises a generally cylindrical valve body 12' having a connection 13 'with a male thread extending from its lower end and a reset mechanism 14' extending from its upper end. From the upper end of the body 12 ', a cylindrical neck 16'
Extends radially and includes a rotatable coupler 17 '.
Is attached. An optional access port 18 'is diametrically opposed to the neck 16' and is sealed by a threaded plug 19 '.

The reset mechanism 14 'has a neck portion 51' having an external thread and extending axially from the cylindrical valve body 12 'toward the distal end. The spindle 5 has a minimum clearance in the distal opening of the bore for sliding translation.
2 'is extended. A pin 53 'extends axially from the spindle 52' toward the base, the lower end of which extends into the cylindrical side wall of the valve element assembly. Sleeve 5
4 'is attached to the neck 51' and holds the spindle 52 'in the bore, and a second O-ring seal 56' is attached to the spindle 52 'to prevent gas flow over the spindle 52'. A compression spring 57 'is provided around the spindle 52' and urges the reset mechanism 14 'to translate toward the distal end. A button end 58 'is provided outside the spindle 52' to facilitate manual engagement.

The sleeve 54 'is approximately the same length as the outer projection of the spindle 52' and the button end 58 ',
The inner opening of sleeve 54 'is dimensioned to be close to button end 58'. By bringing the sleeve close to the push button, intrusion of dust is prevented, and there is no possibility that external factors may interfere with the push button operation.

In order to reset the valve 11 'to return to normal operating conditions, it is generally necessary to manually push the button end 58' of the spindle 52 '. The button can be pressed only with a thin object having a diameter smaller than the inner diameter of the reset protection sleeve 54 '. Therefore,
No accidental resetting of the valve due to accidental contact of falling objects. The spindle 52 'is a compression spring 57'
The pin 53 'translates toward the base and abuts the valve assembly, biases the valve assembly toward the base and re-opens the flow path. When the button end 58 'is released, the spring 57'
Driving 2 'towards the end, the valve is again positioned to allow normal gas flow and detect any significant gas leaks.

The valve 11 or 11 ′ is a gas consumption measuring device 8.
6 has been described as being configured to be located downstream of and adjacent to the coupling 6, and therefore, typically includes a coupling 1 having 3/4 inch or 1 inch NPT threads.
3 and 17 can be provided. The valve 11 is
For example, it may be configured to be inserted further downstream of the customer supply system, such as where the branch line connects to the pipe 89 or where the branch line connects to the appliance to which it is supplied. In the latter case, the valve 11 can be manufactured without the access port 18 and at least one of the couplings 13 and 17 is provided with a 1/2 inch NPT thread instead of a 3/4 inch NPT thread. be able to. Also, the effective cross-sectional area of the flow path within the valve may be redesigned so that the threshold flow velocity level (described above) is slightly greater than the expected gas draw into a particular instrument or branch line. Multiple models of valve 11 may be manufactured, with each model having a particular threshold flow rate level suitable for the typical consumption rate of the gas appliance.

Referring now to FIGS. 13 and 14,
FIG. 13 shows a gas shutoff valve 131 according to a third embodiment of the present invention.
This valve is identical to the gas shut-off valve 11 'except that it has a male threaded connection 132 instead of the cylindrical neck 16' and the rotatable coupler 17 '. The detachable pipe joint 111 which is a preferred embodiment of the detachable nipple 92 and has a cross section as shown in FIG. 14 is connected to the male connecting portion 132. The detachable fitting 111 includes a tubular member 112 in which a hole 113 extends axially. A pair of annular flanges 114 extend from both ends of the tubular member 112 in the radial direction. Also, a pair of threaded couplings 116 are provided, each attached to a flange end of the tubular member 112, and a gasket seal 115 abuts the flange end. Although the coupling 116 is female in the illustrated preferred embodiment, the invention can be equally well practiced with male ends and unions. Each coupling 116 has an inner threaded outer end and an inner end smaller in diameter than the flange 114 of the tubular member 112, and the coupling 116 is
12 is held. A pair of O-ring seals 118 are provided, one for each coupling 116, and arranged to sealingly engage the outer surface of tubular member 112. Thus, each coupling forms a rotatable sealed engagement with the tubular member.

A groove 121 extends annularly at an intermediate portion of the tubular member 112. As shown in FIG.
Together with the inner hole 113 form a side wall that is thinner than the rest of the tubular member. The thinned side walls have design break points that are more susceptible to breakage under shear loading. The depth of the groove 121 determines the shear rupture strength of the tubular member 112, which may be calculated or measured empirically. Naturally, the strength of the material forming the side wall also determines the shear fracture strength, and the tubular member 112 can be made of a material such as brass, copper, iron, steel, or plastic.

The coupling 1 is provided around the tubular member 112.
A compression coil spring 122 is attached to the inner end of the compression spring 16. The spring 122 provides an elastic restoring force that urges the coupling 116 axially apart and against the flange end 114 of the tubular member 112. This spring 122 has no operational effect on the assembly while the assembly is intact. The spring 122 includes the tubular member 112
Only when the shearing force exerted on the annular groove 121 is sufficient to cause breakage in the thin side wall region of the annular groove 121. When the side wall breaks, as shown in FIG. 15, two non-tensile integrity assemblies A and B with adjacent ends.
Is formed. The restoring force of the spring 122 opens the damaged part and
The two assemblies A and B are separated and serve to create a significant gap C between them.

The detachable pipe joint 111 is a coupling 1
16 is connected to the gas shut-off valve 131 by screwing it into the male connector 132. The other coupling is connected to a downstream pipe leading to a gas consuming device. When the detachable fitting 111 is subjected to a shearing force greater than its shear strength, the detachable fitting 111 is broken, and a sufficient outflow to trigger the valve 131 is secured. In the event of an earthquake, landslide, storm, tornado, flood, or other event that causes a large shear force on the pipe assembly, the detachable fitting 111 acts as a seismic or acceleration sensing valve and cooperates with the gas shutoff valve 131. Then, when the threshold of the earthquake or the acceleration is exceeded, the gas is reliably shut off. Therefore,
The detachable pipe joint 111 and the valve 131 function together as an earthquake sensing automatic gas shutoff valve. It should be emphasized here that even if the detachable fitting 111 is not damaged, any pipe breakage downstream of the fitting 111 will trigger the valve 131. In addition, valve 131 is sensitive to pressure surges in the gas line connected to valve 131 as a source. Thus, the combination of an automatic gas shut-off valve with removable flow and a detachable fitting not only provides protection against earthquakes, but also protects downstream equipment from high-pressure gases that could cause a fire or explosion. .

Although the detachable fitting 111 is specifically shown for use with the automatic gas shut-off valve 131, it will be understood that the detachable fitting 111 works with any valve having an overflow sensing trigger mechanism.

In the preferred embodiment of the detachable pipe joint 111, the thin side wall of the tubular member
1 and a hole 113. The thin side wall portion can be otherwise defined by any method that can form a side wall having a desired shear rupture strength, such as external grinding, stretching of a tubular member, and the like. The axial force of the spring 122 does not affect the shear sensitivity of the thin side wall of the tubular member.

While the invention has been described with reference to a limited number of embodiments, it will be understood that the invention is capable of many variations, modifications, and other applications.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a gas leak detection shutoff valve of the present invention.

FIG. 2 is a plan view of the gas leak detection shut-off valve shown in FIG. 1;

FIG. 3 is an end view showing an outlet of a gas leak detection shutoff valve.

FIG. 4 is a cross-sectional view of the gas leak detection shut-off valve shown in FIGS.

FIG. 5 is a plan view showing the valve element assembly of the present invention.

FIG. 6 is an inner end view showing the pipe joint nipple of the present invention.

FIG. 7 is an enlarged sectional view showing a gas flow path of the valve element assembly of the present invention.

FIG. 8 is a cross-sectional view showing another embodiment of the gas leak detection shutoff valve.

FIG. 9 is a perspective view showing a typical gas supply connection pipe to a consumer premises.

FIG. 10 is a perspective view similar to FIG. 9 showing the installation of a gas leak sensing shut-off valve in a typical gas supply connection to a consumer premises.

FIG. 11 is a cross-sectional view showing another embodiment of the gas leak detection shutoff valve.

12 is a partial cross-sectional view of the reset button protection unit shown in FIG.

FIG. 13 is a plan view showing a third embodiment of a gas leak detection shut-off valve including a preferred embodiment of a detachable pipe joint.

FIG. 14 is a cross-sectional view showing the detachable pipe joint shown in FIG. 13 in a fluid-containing state without damage.

FIG. 15 is a cross-sectional view showing the detachable pipe joint shown in FIGS. 13 and 14 in a damaged leak state.

FIG. 16 is a cross-sectional view showing a modification of the gas leak detection shut-off valve of FIGS.

[Explanation of symbols]

 11, 11'131 Gas leak detection valve 12, 12 'Valve body 14, 14' Reset mechanism 18, 18 'Access port 21 Inner hole 23 Valve chamber 26 Fitting nipple 41, 41' Valve assembly 44 ', 46 Gasket 52, 52 'spindle 53, 53' pin 58, 58 'button end 92 detachable nipple 93, 121 annular groove 111 detachable pipe joint 112 tubular member 116 coupling 122 coil spring

Continued on the front page (72) Inventor Joel Schuster, Israel, Holon 58117, P-A Box 1741, Hasadona Street 28

Claims (26)

[Claims] 1. A gas leak detection shut-off valve used in a gas supply line, comprising: a valve body having an inner hole extending in an axial direction inside the valve body; A first fitting means that can be connected to a supply source; a discharge path means connected to the second end of the bore; a connection to an outer end of the discharge path that can be connected to a gas delivery system. Second fitting means, valve chamber means disposed at an intermediate portion of the bore, an annular gasket dimensioned to form a seal with an annular step of the valve chamber, and disposed within the valve chamber. A valve assembly extending from the source of pressurized gas through the first fitting means to the valve chamber, around and within the valve assembly, and through the exhaust passage to a gas delivery system. And the gas flow A gas passage adapted to allow the valve assembly to translate axially within the gas passage from a first position that releases the gas passage to a second position that closes the gas passage; less than the valve A threshold gas flow rate driven by the gas flow such that the assembly is held in the first position and beyond which the valve assembly translates to the second position to shut off the gas flow. Means for determining, comprising a spindle slidably mounted at a second end of the bore and a pin extending from the spindle toward the valve assembly, for moving the valve assembly from the second position to the first position. Reset means for manually biasing the translation; a reset button formed on the outer end of the spindle;
And a means for protecting the reset button from the impact of falling objects. 2. The gas leak sensing device according to claim 1, wherein said reset button protection means includes a generally cylindrical sleeve extending from said valve body and disposed coaxially around said reset button. Shut-off valve. 3. The gas leak detection shut-off valve according to claim 2, wherein the sleeve extends outwardly from the valve body by substantially the same length as an outer protrusion of the reset button. 4. The gas leak sensing shutoff of claim 1 further comprising spring means for biasing said spindle to translate outwardly from said second end of said bore into said sleeve. valve. 5. The gas leak of claim 1, wherein said first fitting means includes a first member having a first fitting bore and an inner end extending into said valve chamber. Sensing shutoff valve. 6. The threshold gas flow rate determining means includes at least one slot formed in the inner end of the first member to allow a flow of gas into the valve chamber. The gas leak detection shut-off valve according to claim 5, wherein 7. When the valve assembly is disposed in the first position, the valve assembly abuts on an inner end of the first member, and the gas flow path is provided in the first position. 7. A gas leak sensing shut-off valve according to claim 6, wherein said valve extends from said fitting means through said at least one slot at the inner end of said first member. 8. The valve assembly includes a cup-shaped valve assembly having a closed lower end and an upper end open toward the second end of the flow path, wherein the spindle extends through an upper end of the valve assembly. 2. The gas leak sensing shut-off valve of claim 1, wherein said shut-off valve is sized to abut a closed lower end of said valve assembly. 9. The valve assembly includes a parasol-shaped valve assembly having a slotted head opening toward a second end of the flow passage, such that the spindle abuts the head of the valve assembly. 2. The gas leak detection shut-off valve according to claim 1, wherein the shut-off valve has various dimensions. 10. The valve of claim 1, further comprising an access opening extending from the exterior of the valve body to the bore, the access opening being substantially diametrically opposed to the discharge passage means. Gas leak detection shut-off valve. 11. The gas leak according to claim 10, wherein said access port includes a female thread and further includes a plug having a corresponding thread on the outside for sealingly engaging within said access port. Sensing shutoff valve. 12. The valve body, the exhaust passage, and the access port defining a T-shaped structure sized to replace a T-shaped fitting in a standard gas supply pipe for a consumer premises. The gas leakage detection shut-off valve according to claim 11, characterized in that: 13. A detachable fitting for a gas piping system, comprising: a pair of couplings connectable to a gas piping system, the pair comprising a hole extending axially through the coupling. A tubular member extending axially therebetween; means for forming a rotatable seal between the tubular member and the pair of couplings; breakage in response to a predetermined shear load exerted on the pair of couplings A detachable fitting comprising: a shear failure means in the tubular member forming a portion; and means for separating the failure portion to form a major tear in the piping system. 14. The breakage separating means includes spring means mounted between the pair of couplings for biasing the pair of couplings to separate axially. 14. The detachable pipe joint according to 13. 15. The detachable pipe joint according to claim 14, wherein the spring member includes a coil spring mounted around the tubular member and abutting on the pair of couplings in a compressed state. . 16. The detachable pipe joint according to claim 13, wherein said shear breakage means includes means defining a thin side wall of said tubular member. 17. The detachable pipe joint according to claim 16, wherein said means for defining said thin side wall portion includes an annularly extending groove in an outer surface of said tubular member. 18. The detachable pipe joint according to claim 17, wherein the groove is disposed at an intermediate portion between the pair of couplings. 19. The breakage separating means includes spring means mounted between the pair of couplings for biasing the pair of couplings to separate axially. 19. The detachable pipe joint according to 18. 20. The detachable pipe joint according to claim 19, wherein the spring member includes a coil spring mounted around the tubular member and abutting on the pair of couplings in a compressed state. . 21. The means for forming a rotatable seal includes a pair of flanges formed at opposite ends of the tubular member and dimensioned to be received within the pair of couplings. The detachable pipe joint according to claim 13, characterized in that: 22. The means for forming a rotatable seal includes a pair of O-ring seals mounted within the pair of couplings and arranged to abut the tubular member. 14. The detachable type pipe joint according to claim 13. 23. The detachable pipe joint according to claim 13, wherein at least one of the pair of couplings comprises a female coupling having a threaded inner hole. 24. The gas line delivery system comprising: an excess gas flow automatic shutoff valve; means for connecting the valve in series with a gas tube delivery system; and shear failure means for forming a break in response to an earthquake of a predetermined magnitude. Detachable fitting means connected downstream of the valve in the system and the breakage so as to create a breach in the gas pipe delivery system sufficient to trigger the excess gas flow automatic shutoff valve. Automatic gas shut-off system including means for separating. 25. The detachable fitting means includes a tubular member connected to the gas pipe delivery system for passing the gas flow, wherein the shear breaking means has an annular shape having a predetermined shear breaking strength. The automatic gas shut-off system according to claim 24, including a side wall of the member. 26. The automatic apparatus according to claim 24, wherein the broken part separating means includes a coil spring mounted around the tubular member in a compressed state so as to apply an elastic restoring force to the broken part. Gas shut-off system.