JP2002157021A - Pressure reducing valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reducing valve capable of preventing leakage in the event of breakage of a pressure-displacement converting element such as diaphragm, piston or the like. SOLUTION: This pressure reducing valve comprises an air passing passage 28 communicating with the outside, which is provided within a spring chamber 16 water-tightly sealed by a pressure-displacement converting element 14 connected to a valve element 6 through a valve rod 23 and displaced by the pressure fluctuation of a secondary pressure chamber 4 and a spring cover 13 containing a regulating spring 15 for energizing the pressure-displacement converting element 14 to the opening direction of the valve element 6. Air is generally passed to the spring chamber 16 to prevent the fluctuation of the internal pressure of the spring chamber 16 by a temperature change. A means 30 for water-tightly blocking the air port 29 of the air passing passage 28 by the pressure water entered thereto from the secondary pressure chamber 4 through the spring chamber 16 in the breakage of the pressure-displacement converting element 14 is provided in the air passing passage 28, whereby the leakage is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing valve for dealing with breakage of a pressure-displacement conversion element such as a diaphragm and a piston.

[0002]

2. Description of the Related Art Conventionally, a pressure-displacement conversion element such as a diaphragm or a piston, which is connected to a valve body via a valve rod and is displaced by a pressure fluctuation of a secondary side pressure chamber, is provided on an upper portion of a valve box of a pressure reducing valve. A spring chamber surrounded by a spring cover containing an adjustment spring for biasing the pressure-displacement conversion element in the valve opening direction of the valve element. An adjustment screw for elastically pressing the adjustment spring is provided at the upper end of the spring cover. At the same time, a small hole-shaped ventilation port communicating with the outside is opened on the side of the spring cover to allow air to flow through the spring chamber so that the internal pressure of the spring chamber does not change even when the temperature changes. ing.

[0003]

[Problems to be solved by the invention] However,
When the diaphragm built in the pressure reducing valve or the O-ring provided around the piston is damaged and pressurized water flows into the spring chamber, the gap between the screw portions of the adjusting screw screwed into the spring cover,
Water leaks from the vent, and the area around the pressure reducing valve is flooded. Such a failed pressure-reducing valve not only fails to perform its function, but also leaks water, for example, in a water heater, an electric water heater, or the like provided in an electric water heater or the like, causing a power distribution board installed near the pressure-reducing valve to leak. Problems such as danger had occurred. An object of the present invention is to provide a pressure reducing valve that can prevent water leakage when a pressure-displacement conversion element such as a diaphragm or a piston is broken.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a pressure-displacement conversion element that is connected to a valve body via a valve rod and that is displaced by pressure fluctuations in a secondary pressure chamber. In a spring chamber which is hermetically sealed with a spring cover containing an adjustment spring for biasing the pressure-displacement conversion element in the valve opening direction of the valve element,
An air flow passage communicating with the outside is provided, and usually air is circulated through the spring chamber so that the internal pressure of the spring chamber does not change even when the temperature changes. And, by providing a means for closing the ventilation port of the air flow passage in a watertight manner by the pressure water flowing from the secondary pressure chamber through the spring chamber when the pressure-displacement conversion element is broken in the air flow passage. The above-mentioned problem is solved by preventing water leakage.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 is a main body of the pressure reducing valve according to the present invention, and the main body 1 includes a vent emergency closing device 2.
The main body 1 includes a valve box 5 provided with a primary pressure chamber 3 and a secondary pressure chamber 4, and a valve body 6 that is incorporated in the valve box 5 and that responds to pressure fluctuations in the secondary pressure chamber 4. It mainly comprises a pressure reducing mechanism 7 for controlling the opening.

The valve box 5 has an inlet 8 and an outlet 9 on both left and right sides thereof, and has a primary pressure chamber 3 and a secondary pressure chamber 4 communicating with the inlet 8 and the outlet 9 therein. Provided. In the center of the valve box 5, a partition 10 is provided which vertically partitions the primary pressure chamber 3 and the secondary pressure chamber 4, and a valve port 11 is provided in the partition 10.
And the two pressure chambers 3 and 4 are communicated.

The pressure reducing mechanism 7 is formed in an upper part of the valve box 5 and has a substantially circular recess formed in communication with the secondary pressure chamber 4.
12 and a substantially hat-shaped spring cover 13 are joined and fixed via a diaphragm 14 which is a pressure-displacement conversion element, and an upper space defined by the diaphragm 14 and the spring cover 13 (corresponding to the inside of the spring cover 13). An adjustment spring 15 is provided to form a spring chamber 16. The adjusting spring 15 includes a diaphragm holder 17 that is also used as a diaphragm holder and is joined to the upper surface of the diaphragm 14.
The compression cover is interposed between the spring cover 13 and an adjusting screw 19 which also serves as a spring receiver and is screwed to a cylindrical female screw portion 18 formed to hang down from the upper end of the spring cover 13. Then, the upper adjustment screw 19 is moved up and down to adjust the elastic force of the adjustment spring 15 and adjust the displacement of the diaphragm 14 below the adjustment spring.

An adjusting screw 19 is provided on the upper end of the spring cover 13.
A sealing means 20 for covering the spring chamber 16 in a watertight manner is provided detachably, and the spring chamber 16 is sealed in a watertight manner. This sealing means 20
A disk portion 20a having a larger diameter than the female screw portion 18 and a screw rod 20b suspended from the center of the disk portion 20a, and the screw rod 20b is screwed to the center of the adjusting screw 19 to form the disk portion 20a. The O-ring 20c provided at the lower portion is pressed against the upper end surface of the spring cover 13, and the adjusting screw 19 is closed in a watertight manner. The diaphragm 14 is damaged, and the pressure water flowing from the secondary pressure chamber 4 into the spring chamber 16 is prevented from leaking from the gap between the female screw portion 18 and the adjusting screw 19. The adjustment of the elastic force of the adjusting spring 15 by the adjusting screw 19 can be achieved by once removing the sealing means 20 from the adjusting screw 19 and removing it, and moving the adjusting screw 19 up and down. Note that the sealing means 20 is not limited to the above-described configuration, and may use a gasket or other sealing material. In other words, as long as the gap between the screw portions of the adjusting screw 19 can be sealed, the spring chamber 16 can be hermetically sealed. good.

In the recess 12, a circular opening 21 is provided in the lower center corresponding to the valve port 11 so that the primary side pressure chamber 3 is formed.
And a cylindrical portion 22 having a predetermined length is provided continuously below the opening 21. At the center of the diaphragm 14, a valve stem 23 passing through the cylindrical portion 22 and the valve port 11 is formed in a hanging manner. At a lower end of the valve stem 23, a valve body 6 for opening and closing the valve port 11 is provided. . The valve body 6 receives the primary pressure in the valve opening direction,
It is provided so as to be able to be freely attached to and detached from a valve seat 24 provided around the periphery 11, and the degree of opening is controlled by the displacement of the diaphragm 14. A piston 25 that slides on the inner wall of the cylindrical portion 22 is provided at an intermediate position of the valve stem 23, and an O-ring 26 is provided around the piston 25. 12 (secondary pressure chamber 4) is partitioned in a watertight manner. The diaphragm retainer 27 joined to the lower surface of the diaphragm 14 is formed to have a larger diameter than the opening 21, and in a state where the diaphragm 14 is displaced to the lowermost limit, the diaphragm retainer 27 is seated on the periphery so as to close the opening 21. In this state, the lift of the valve body 6 is regulated.

The emergency vent closing device 2 is a closing means 30 provided in an air flow passage 28 which communicates with the outside of the spring chamber 16. The air outlet 29 of the air flow passage 28 is closed in a water-tight manner by pressure water flowing from the fourth through the spring chamber 16 into the air flow passage 28. The closing means 30 will be described in detail. First, the air flow passage 28 is formed so as to protrude horizontally on the side of the spring chamber 16, and forms a cylindrical water flow cutoff chamber 31 having an air vent 29 at the upper end in the air flow passage 28. As shown in FIGS. 3 and 4, the water shutoff chamber 31 is provided with a spherical float valve 32 having a diameter smaller than the inner diameter thereof and larger than the vent hole 29. mouth
29 is provided with a continuous water flow shutoff valve seat 33. The valve seat 33 for water flow shutoff is an enlarged diameter opening at the lower end of a substantially funnel-shaped through hole 35 formed continuously from the air hole 29 in a rubber seat 34 interposed between the air vent 29 and the upper part of the water flow shutoff chamber 31. Yes, water flow cutoff room 31
When the float valve 32 that floats due to the pressurized water flowing into the inside is seated, the ventilation port 29 is closed in a watertight manner. In addition, in the lower part of the water flow cutoff chamber 31, a normal (diaphragm)
(14 is not damaged) An emergency opening valve seat 36 on which the float valve 32 is seated is provided. This emergency opening valve seat 36 is
The inside of the C-shaped ring fixed to the lower part of the water flow cutoff chamber 31 is cut off so as to be continuous with the emergency release valve seat 36 and forms an air flow port 37, and floats on the emergency release valve seat 36. Valve 32
Is seated, and the water flow shutoff chamber 31 is
And the spring chamber 16 communicate with each other.

In this embodiment, the pressure applied to the body 1
Although the displacement conversion element 14 is shown as being composed of a diaphragm, a piston may be used as the pressure-displacement conversion element 14 as shown in FIGS. In this case, the spring cover 13 and the concave portion 12 are joined via a seal member, and a piston 14 is disposed in the concave portion 12 so as to be vertically movable, and an O-ring 38 provided around the piston 14 slides on the inner wall of the concave portion 12. It is configured to move.

Next, the operation of the pressure reducing valve according to the present invention will be described. In the normal case where the pressure-displacement conversion element 14 is not damaged, the main body 1 performs the original function of the pressure reducing valve. That is, the upward (valve closing direction) force applied to the pressure-displacement conversion element 14 by the secondary pressure and the downward (valve opening direction) force by the adjusting spring 15 are balanced, so that the opening degree of the valve body 6 is increased. It is controlled to maintain a constant pressure at which the secondary pressure is lower than the primary pressure. At this time, as shown in FIGS. 1 and 3 to 5, the float valve 32 of the ventilation port emergency closing device 2 is
31 is seated on the emergency release valve seat 36 at the lower portion, but is connected to the air flow passage 28 at the upper end of the water flow shutoff chamber 31 by the air flow opening 37 opened adjacent to the emergency release valve seat 36. Is communicated with the outside, the air flows through the spring chamber 16, and the internal pressure of the spring chamber 16 does not change even when the temperature changes.

In the event that the pressure-displacement conversion element 14 of the main body 1 is damaged (in the case of the piston 14, the O-ring 38 is worn or broken), the pressure water in the secondary pressure chamber 4 is released from the spring chamber 16 2 and 6, the float valve 32 floats and is seated on the water flow shutoff valve seat 33 by the pressure water flowing into the water flow shutoff chamber 31 of the air flow passage 28 via the spring chamber 16 as shown in FIGS. Vents 29
To prevent water leakage from the vent hole 29. still,
When the spring chamber 16 is filled with the pressurized water, the water that tends to leak to the outside through the gap of the screw portion of the adjustment screw 19 screwed to the spring cover 13 is stopped by the sealing means 20. The spring chamber 16 is a space closed in a watertight manner, and the pressurized water filled in the spring chamber 16 operates the float valve 32 of the vent emergency closing device 2. 2 and 6 show the emergency vent closing device 2 when the pressure-displacement conversion element 14 is broken.
In these figures, the pressure-displacement conversion element 14 originally shows a broken state.
For convenience, the pressure-displacement conversion element 14 is not shown as broken,
This has been described above.

[0014]

In short, the present invention relates to a pressure-displacement conversion element 14 which is connected to a valve body 6 via a valve rod 23 and which is displaced by the pressure fluctuation of the secondary pressure chamber 4; element
Since the spring chamber 16 is hermetically sealed with the spring cover 13 having the adjustment spring 15 for biasing the valve body 14 in the valve opening direction of the valve body 6,
Even if the pressure-displacement conversion element 14 is damaged and the pressure water in the secondary pressure chamber 4 flows into the spring chamber 16, the pressure water does not flow out of the spring chamber 16 to the outside. Thus, the closing means 30 of the air flow passage 28 can be operated. Also, since the air passage 28 communicating with the outside is connected to the spring chamber 16,
As in the case of the conventional pressure reducing valve, normally, air is circulated to the spring chamber 16 through the air flow passage 28, and the internal pressure of the spring chamber 16 is not changed even by a change in temperature, so that it can function as a pressure reducing valve without any trouble. Further, when the pressure-displacement conversion element 14 is broken, the air flow passage 28 is moved from the secondary pressure chamber 4 to the spring chamber 16.
Through the air flow passage 28
The provision of the means 30 for closing the 29 in a water-tight manner allows the spring chamber 16 to prevent water leakage from the ventilation port 29 that is solely connected to the outside, whereby the periphery of the pressure reducing valve is flooded and the vicinity of the pressure reducing valve is reduced. It is possible to solve the problem that the installed switchboard or the like leaks. As described above, according to the present invention, the pressure-displacement conversion element 14 is damaged, and the pressure water in the secondary pressure chamber 4 is released from the spring chamber 16.
Even if a situation occurs, the pressurized water is prevented from flowing out of the spring chamber 16 to the outside, and the vent hole 29 of the air flow passage 28 connected to the spring chamber 16 is watertight using the pressurized water. In this way, the water is shut off and stopped, and the outflow of the pressure water from the secondary pressure chamber 4 to the outside can be completely prevented.

In the air passage 28, a vent is provided at the upper end.
A water flow cutoff chamber 31 provided with a water flow shutoff chamber 31 is formed upright, a float valve 32 is provided in the water flow cutoff chamber 31, and a valve seat 36 for emergency opening of the float valve 32 is provided below the water flow cutoff chamber 31; When the float valve 32 is seated on the valve seat 36, the airflow opening 37 for communicating the water flow shutoff chamber 31 and the spring chamber 16 is provided, so that the pressure reducing valve main body 1 does not normally fail as described above. Air can flow between the outside and the spring chamber 16 to prevent the internal pressure from changing even if the temperature of the spring chamber 16 changes, and the main body 1 can function normally. Also, should the pressure-displacement conversion element
A water flow shutoff valve seat 33 of a float valve 32 connected to a vent 29 is provided above the water flow shutoff chamber 31 even if the pressure water in the secondary pressure chamber 4 flows into the spring chamber 16 due to the breakage of 14. As a result, the pressure water flowing from the spring chamber 16 into the water shutoff chamber 31 causes
By floating the float valve 32 seated on the valve, the float valve 32 is seated on the water flow shutoff valve seat 33, thereby closing the vent hole 29 in a water-tight manner and preventing water leakage from the vent hole 29. . Thus, the closing means 30 is configured with a simple structure,
The function of circulating air to the spring chamber 16 in the normal state and the emergency closing of the ventilation port 29 in the event of a failure can be implemented.

Also, since the adjusting means 19 for pressing the adjusting spring 15 screwed to the spring cover 13 is removably provided with the sealing means 20 for covering the adjusting screw 19 in a watertight manner, the spring chamber 16 can be closed in a watertight manner.
Even when the pressure water from the secondary pressure chamber 4 flows into the spring chamber 16, the pressure water does not leak from the gap of the screw portion of the adjustment screw 19 screwed to the spring cover 13. The pressurized water in 16 can be used as power transmission means for closing means 30. In addition, at normal times, when changing the elastic force of the adjusting spring 15, the elastic force of the adjusting spring 15 can be adjusted with the adjusting screw 19 by just removing the sealing means 20, without any difference from the previous operation. The practical effect is enormous.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a normal use state of a pressure reducing valve.

FIG. 2 is a cross-sectional view when a pressure-displacement conversion element is broken.

FIG. 3 is an enlarged view of the vent emergency closing device in the state of FIG. 1;

FIG. 4 is a sectional view taken along the line AA of FIG. 3;

FIG. 5 is a sectional view showing a normal use state in another embodiment.

FIG. 6 is a cross-sectional view when the pressure-displacement conversion element is broken.

[Explanation of symbols]

 4 Secondary pressure chamber 6 Valve 13 Spring cover 14 Pressure-displacement conversion element 15 Adjusting spring 16 Spring chamber 19 Adjusting screw 20 Sealing means 23 Valve rod 28 Air flow passage 29 Vent 30 Closing means 31 Water flow shutoff chamber 32 Float valve 33 Water flow shutoff valve seat 36 Emergency release valve seat 37 Air circulation port

Claims (3)

[Claims] 1. A valve body connected to a valve body through a valve stem.
A spring that is hermetically sealed by a pressure-displacement conversion element that is displaced by pressure fluctuations in the secondary pressure chamber and a spring cover that contains an adjustment spring that biases the pressure-displacement conversion element in the valve opening direction of the valve element. The chamber is provided with an air flow passage communicating with the outside, and the pressure-displacement conversion element is damaged by the pressure water flowing in from the secondary pressure chamber via the spring chamber in the air flow passage. A pressure reducing valve provided with a means for closing a vent in a watertight manner. 2. An air flow passage, wherein a water flow cutoff chamber having a vent at its upper end is formed upright, a float valve is provided in the water flow cutoff chamber, and an emergency valve seat for the float valve is provided below the water flow cutoff chamber. And an air flow opening through which the water flow shutoff chamber and the spring chamber communicate with each other when the float valve is seated on the emergency release valve seat. The pressure reducing valve according to claim 1, further comprising a valve seat. 3. The pressure-reducing valve according to claim 1, wherein an adjusting screw for resiliently pressing an adjusting spring screwed onto the spring cover is provided with a sealing means for covering the watertight seal in a detachable manner.