JPH0434294Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a meter protection device that prevents abnormal pressure from being applied to a gas meter.

[Prior art and its problems] When a valve on the upstream side of a gas meter is opened instantaneously, extremely high pressure may temporarily act on the gas meter, causing damage to the gas meter.

For this reason, in the past, the valves of gas appliances were manually opened gradually to prevent accidents, but with the use of solenoid valves, the valves can be operated instantly. Therefore, the gas meter may be damaged if a momentary large gas pressure is applied to the gas meter. Currently, in order to prevent such accidents, the structure of the gas meter is made stronger, but this method has the disadvantage that the manufacturing cost of the gas meter is high.

In addition, a washing machine water supply amount adjustment device (Utility Model Publication Act, 1973-1993) was devised to prevent a large amount of water from flowing through the action of a valve body built into the water supply flow path when the water supply pressure temporarily increases. 24541) is publicly known. but,
In the case of this known example, since the valve body is directly supported by a spring, if it is desired to change the operating pressure of the valve body, the spring must be replaced, which poses a problem of cost and effort.

The present invention has been proposed in view of the above, and an object of the present invention is to provide a gas meter protection device incorporating a function that allows the operating pressure of the valve body to be easily changed.

[Means to solve the problem] The configuration of the present invention is as follows.

A gas passage is formed in the main body, and a valve seat is formed in a part of the gas passage, and the valve seat can be freely adhered to from the upstream side,
A safety valve with a flow restriction hole in a part is fixed to the thrust shaft, and this thrust shaft is supported by the upstream bearing frame of the main body, and on the downstream side, it is screwed into a screw formed on the main body, and its displacement can be adjusted up and down. A spring is interposed between the safety valve and the bearing frame, and the elastic force of the spring is applied to the valve seat when the safety valve is separated from the valve seat upstream at normal pressure, and the valve seat is opened. A gas meter protection device characterized by being set so that it comes into close contact with a valve seat at abnormal pressures.

[Operation] When the solenoid valve on the gas appliance side is opened and instantaneously acts on the large safety valve, the safety valve moves down against the spring and comes into close contact with the valve seat. As a result, no large pressure acts on the gas meter side.
However, the minimum flow rate is ensured by the flow rate restriction hole, and when the pressure returns to normal pressure, the safety valve returns to its original position by the force of the spring.

If the pressure acting on the safety valve changes as a result of replacing the gas appliance, the screwing amount of the downstream bearing frame is adjusted accordingly, thereby adjusting the elastic force of the spring.

[Embodiment] Fig. 1 shows a safety device according to an embodiment of the present invention, in which 1 is a main body having a gas passage 2 inside, 3 is a connecting flange formed at both ends of this main body 1, and 4 is a gas passage. 2, a valve seat formed in the upstream body 1; On the other hand, the safety valve 6 is attached to a thrust shaft 7 that is slidably inserted, and the safety valve 6 can be brought into close contact with the valve seat 4 from the upstream side. 8 is a flow rate restriction hole opened in the safety valve 6, and even if the safety valve 6 is in close contact with the valve seat 4, a certain amount of gas can flow through the flow rate restriction hole 8.

9 is a spring that always pushes the safety valve 6 back to the open side, and the elastic force of this spring 9 is set so that it prevails up to a range slightly higher than normal pressure, but loses against abnormal pressure that would damage the gas meter. 14 is the thrust bearing 7 attached to the main body 1.
This bearing frame 14 is screwed onto the screw 1b on the main body 1 side, and is displaced up and down to support the spring 9.
The elastic force can be adjusted.

Figure 3 shows the above safety device installed on a Roots gas meter 10.
An example is shown in which the ball valve 11 on the upstream side is opened and the gas pressure suddenly increases to the safety valve 6.
When this occurs, the safety valve 6 pushes the spring 9 into close contact with the valve seat 4, temporarily restricting the flow of gas. Then, gas flows downstream from the flow rate restriction hole 8 and the gas pressure on the downstream side increases, and when the pressure reaches a level where there is no risk of damage to the Roots gas meter 10, the safety valve 6 is separated from the valve seat 4 by the force of the spring 9 and the gas passage 2 will be fully opened.

Figure 4 shows the gas inlet 1 of the medium pressure membrane gas meter 12.
3 shows an example incorporating the safety device of the present invention,
Particularly in the case of membrane gas meters, the strength of the membrane is weak, so it is effective to incorporate the safety device of the present invention.

[Effects of the present invention] As described above, the present invention is a device that can be installed on the upstream side of a gas meter, and
A safety valve is provided that operates to restrict the flow of gas when the gas pressure suddenly increases, so even if the gas valve were to open instantly, abnormal pressure would not act on the gas meter. Therefore, there is an effect that damage to the gas meter can be prevented.

Next, since the elastic force of the spring can be adjusted using the downstream bearing frame, it is convenient to easily adjust the operating pressure of the spring to the optimum operating pressure when the gas appliance is changed.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the safety device according to the present invention, Figure 2 is a sectional view of the safety device according to the present invention.
The figure is a front view, FIG. 3 is an embodiment in which the safety device of the present invention is installed in roots meter piping, and FIG. 4 is an embodiment in which the safety device of the present invention is installed in a medium pressure membrane type gas meter. DESCRIPTION OF SYMBOLS 1...Main body, 2...Gas passage, 3...Flange, 4...Valve seat, 5...Upstream bearing frame, 6...
... Safety valve, 7 ... Thrust shaft, 8 ... Flow rate restriction hole, 9 ... Spring, 10 ... Roots gas meter, 11 ... Ball valve, 12 ... Medium pressure membrane gas meter, 13 ... Gas inlet, 14 ... ...Downstream bearing frame.

Claims (1)

[Claims for Utility Model Registration] A gas passage 2 is formed in the main body 1, and a valve seat 4 is formed in a part of the gas passage 2, and the valve seat 4 can be attached to the valve seat 4 from the upstream side. A safety valve 6 having a flow rate restriction hole 8 in its part is fixed to a thrust shaft 7, and this thrust shaft 7 is supported by an upstream bearing frame 5 of the main body 1 and is screwed into a screw 1b formed in the main body 1 on the downstream side. and is supported by a downstream side bearing frame 14 whose displacement can be adjusted up and down, and a spring 9 is interposed between the safety valve 6 and the bearing frame 14, and the elastic force of the spring 9 is applied so that the safety valve 6 reaches the valve seat at normal pressure. 4. A gas meter protection device characterized in that the valve seat is separated from the valve seat 4 on the upstream side and is set to be in close contact with the valve seat 4 at abnormal pressure.