JP7233673B2 - Leak inspection valve - Google Patents

Description

The present invention relates to a leak inspection valve.

A water supply system installed in a building or the like is leak-tested as follows. That is, when the test fluid is sealed in a high-pressure state in the piping of the water and hot water supply system, and the amount of pressure drop in the piping after a predetermined time has passed in that state is equal to or greater than the judgment value, a leak occurs in the water and hot water supply system. It is determined that In the leak inspection, a leak inspection valve is used when sealing the test fluid in the pipe. As such a leak inspection valve, it is conceivable to use, for example, a pipe joint integrally provided with a stop cock disclosed in Patent Document 1.

The pipe joint includes a body formed with a pipe connection port connected to a pipe of a hot water supply system to be tested, and a pump connection port connected to a pump that discharges test fluid. Further, the body of the pipe joint is formed with a partition wall for partitioning a pipe-side passage connected to the pipe connection port and a pump-side passage connected to the pump connection port. The partition wall is formed with a communication hole connecting the pump-side passage and the pipe-side passage, and a valve seat surrounding the communication hole. Further, a spindle for opening and closing the communication hole is provided on the body of the pipe joint so as to be displaceable in the axial direction. In the above pipe joint, the communication hole is opened and closed by moving the spindle toward and away from the valve seat through axial displacement of the spindle.

5 and 6 show the peripheral structure of the spindle and valve seat in the body of the pipe joint. As can be seen from these figures, the partition wall 72 of the body 71 partitions the pump-side passage 73 and the pipe-side passage 74, and the spindle 75 is displaced in the axial direction (vertical direction in FIG. 5) to move the partition wall. It approaches and separates from the valve seat 77 around the communicating hole 76 at 72 . A packing 78 is provided at the end of the spindle 75 on the valve seat 77 side. The packing 78 is attached to the end portion of the spindle 75 by a shaft portion 75a formed at the end portion of the spindle 75 penetrating therethrough. The shaft portion 75a of the spindle 75 has a tip end (lower end in FIG. 5) with a larger diameter than other portions, thereby making it difficult for the packing 78 to come off the shaft portion 75a. The packing 78 is formed with a tapered surface 79 whose diameter decreases toward the valve seat 77 side. This tapered surface 79 abuts against the valve seat 77 through displacement of the spindle 75 toward the valve seat 77 shown in FIG.

When performing a leak test for a water supply and hot water supply system, the pipe connection port of the pipe joint is connected to the pipe of the water and hot water supply system, while a pump that discharges test fluid is connected to the pump side connection port of the pipe joint. be done. Then, the test fluid discharged from the pump is supplied into the piping of the hot water supply system to set the inside of the piping to a high pressure state, and under this state, the spindle 75 of the pipe joint is directed toward the valve seat 77 in the axial direction. , the tapered surface 79 of the packing 78 is brought into contact with the valve seat 77 of the body 71 . At this time, the space between the tapered surface 79 and the valve seat 77 is sealed and the communication hole 76 is closed through the spindle 75, so that the test fluid is sealed in the piping of the hot water supply system in a high pressure state. The reason why the packing 78 is formed with the tapered surface 79 whose diameter decreases toward the valve seat 77 is that it is necessary to increase the contact area between the tapered surface 79 and the valve seat 77 to increase the contact area between the two. This is to ensure the required sealing performance.

Japanese Patent Application Laid-Open No. 2001-182108

By the way, in enclosing the test fluid in the piping of the hot water supply system, the pipe joint may be operated as follows depending on the requirements based on the specifications of the pump and the requirements based on the work procedure of the leak inspection. That is, under the condition that the communication hole 76 of the pipe joint is closed by the spindle 75 as shown in FIG. 6, the test fluid is discharged from the pump to fill the pump side passage 73 with the high pressure test fluid. Thereafter, as shown in FIG. 5, by displacing the spindle 75 in the direction away from the valve seat 77 to open the communication hole 76, the test fluid in the pump side passage 73 passes through the piping side passage 74 to the piping of the hot water supply system. supply within. After the pipes of the water and hot water supply system are filled with the high-pressure test fluid, the communication hole 76 is closed by the spindle 75 to seal the test fluid in the high-pressure state in the pipes of the water and hot water supply system.

However, when the pump-side passage 73 is filled with the high-pressure test fluid while the communication hole 76 is closed by the spindle 75 , the pressure of the test fluid acts on the packing 78 of the spindle 75 . Here, since the packing 78 has a tapered surface 79, a portion of the packing 78 farther from the shaft portion 75a of the spindle 75 has a smaller length in the axial direction of the spindle 75 and has a higher rigidity. descend. Therefore, when the communication hole 76 is opened by displacing the spindle 75 while the pump-side passage 73 is filled with the high-pressure test fluid, the portion of the packing 78 away from the shaft portion 75 a of the spindle 75 is positioned inside the pump-side passage 73 . There is a risk that the packing 78 will be deformed by receiving pressure from the test fluid, and along with this, the packing 78 will come off the shaft portion 75a as shown in FIG.

An object of the present invention is to provide an end portion of the spindle on the valve seat side when opening the communication hole by displacing the spindle in the direction away from the valve seat under the condition that the high-pressure test fluid is filled in the pump-side passage. To provide a leak inspection valve capable of suppressing deformation of a packing provided at a pressure from a fluid to be inspected.

Means for solving the above problems and their effects will be described below.
A body of a leak test valve that solves the above problems has a pipe connection port connected to a pipe to be tested and a pump connection port connected to a pump that discharges test fluid. A partition wall is formed in the body to separate the pipe-side passage leading to the pipe connection port from the pump-side passage leading to the pump connection port. A connecting hole and a valve seat surrounding the communication hole are formed. Further, a spindle for opening and closing the communication hole is provided in the body so as to be displaceable in the axial direction. The communication hole is opened and closed by moving the spindle toward and away from the valve seat through axial displacement of the spindle. The end of the spindle on the side of the valve seat is provided with a packing attached to the same end by a shaft portion formed at the end passing therethrough. This packing has a cylindrical surface parallel to the axis of the spindle and a diameter that decreases from the end of the cylindrical surface on the valve seat side toward the valve seat. a tapered surface that contacts the valve seat. The length of the cylindrical surface in the axial direction of the spindle is longer than the length of the tapered surface in the axial direction.

According to the above configuration, in the packing having the cylindrical surface and the tapered surface, the length of the spindle in the axial direction of the cylindrical surface is longer than the length of the tapered surface in the axial direction. The length in the axial direction is longer in the portion away from the shaft. As a result, the reduction in rigidity of the portion of the packing away from the shaft portion of the spindle due to the formation of the tapered surface on the packing is suppressed. Therefore, when the communication hole is opened by displacing the spindle in the direction away from the valve seat under the condition that the high-pressure test fluid is filled in the pump-side passage, the It is possible to suppress the deformation of the portion of the packing away from the shaft of the spindle due to the pressure from the test fluid.

Sectional drawing which shows the whole structure of the valve|bulb for a leak inspection, and a usage condition. Sectional drawing which shows the whole structure of the valve|bulb for a leak inspection, and a usage condition. Sectional drawing which shows the whole structure of the valve|bulb for a leak inspection, and a usage condition. FIG. 4 is a cross-sectional view showing a packing provided on the spindle of the leak inspection valve; Sectional drawing which shows the peripheral structure of the spindle and valve seat in the pipe joint integrally provided with the water stop cock. Sectional drawing which shows the peripheral structure of the spindle and valve seat in the pipe joint integrally provided with the water stop cock. Sectional drawing which shows the peripheral structure of the spindle and valve seat in the pipe joint integrally provided with the water stop cock.

An embodiment of a leak inspection valve will be described below with reference to FIGS. 1 to 4. FIG.
As shown in FIG. 1, the leak inspection valve 1 has a cross-shaped body 2 extending vertically and horizontally in the figure.

A piping connection port 4 connected to a piping 3 of a water supply and hot water supply system installed in a building or the like is formed at the left end of the portion of the body 2 extending in the left-right direction. Specifically, a connection member 3a is attached to the end of the pipe 3, and a connecting member 4a is attached to the end of the body 2 where the pipe connection port 4 opens. is connected to the piping connection port 4 of the body 2 . On the other hand, a right end portion of a portion of the body 2 extending in the horizontal direction is formed with a pump connection port 6 to which a pump 5 for discharging gas such as air as a test fluid is connected. Specifically, a connecting member 32 is attached to the end of the hose 5a extending from the pump 5 by a connecting member 31, and the connecting member 32 is inserted into the pump connection port 6 of the body 2 and connected. A stopper member 33 is attached to the end of the body 2 where the pump connection port 6 opens to prevent the connection member 32 from coming off from the pump connection port 6 .

In addition, in a portion of the body 2 extending in the left-right direction, a pipe-side passage 7 connected to the pipe connection port 4 and extending rightward from the pipe connection port 4 and a pump connection port 6 and a pump connection are provided. A pump-side passage 8 extending leftward from the port 6 and a partition wall 9 for partitioning the pipe-side passage 7 and the pump-side passage 8 are formed. The partition wall 9 is positioned corresponding to a portion of the body 2 extending in the vertical direction. A communication hole 10 for connecting the pump-side passage 8 and the pipe-side passage 7 is formed in the partition wall 9 so that the vertical direction is the center line. A seat 11 is formed. The valve seat 11 has a tapered seat surface 12 whose diameter decreases downward in the centerline direction of the communication hole 10 . A step portion 11 a having an inner peripheral surface parallel to the center line of the communication hole 10 is formed at the upper end portion of the valve seat 11 .

On the other hand, a housing portion 14 for housing a spindle 13 for opening and closing the communication hole 10 is formed in a vertically extending portion of the body 2 above the partition wall 9 . The housing portion 14 is open at its upper end and connected to the pump-side passage 8 at its lower end. A male screw 15 is formed on the outer peripheral surface of the spindle 13 accommodated in the accommodation portion 14 , and the male screw 15 is screwed into a female screw member 16 fixed to the inner peripheral surface of the accommodation portion 14 . The upper end of the spindle 13 protrudes upward from the upper end opening of the accommodating portion 14 . An operating member 17 is bolted to the upper end of the spindle 13 so as to be rotated by an operator.

A seal ring 18 that seals between the inner peripheral surface of the accommodating portion 14 and the spindle 13 is attached to the outer peripheral surface of the spindle 13 below the male thread 15 (the tip side of the spindle 13 ). An annular packing 19 is provided at the end of the spindle 13 on the side of the valve seat 11 . The packing 19 is attached to the end portion of the spindle 13 by passing the shaft portion 13a formed at the end portion. The lower end (tip) of the shaft portion 13a of the spindle 13 has a larger diameter than the other portions, thereby making it difficult for the packing 19 to come off from the shaft portion 13a. The packing 19 is formed with a cylindrical surface 19a parallel to the axis of the spindle 13 and a diameter decreasing from the end of the cylindrical surface 19a on the side of the valve seat 11 toward the valve seat 11. and a tapered surface 19b that contacts the seat surface 12 of the valve seat 11 through displacement toward the seat 11 side.

When the operator rotates the operating member 17 , the spindle 13 rotating with the operating member 17 is axially displaced by the action of the male thread 15 and the female thread member 16 . Specifically, when the operating member 17 is rotated about the axis of the spindle 13 in the forward direction, the action of the male thread 15 and the female thread member 16 displaces the spindle 13 in the axial direction toward the valve seat 11 .

As shown in FIG. 2, when the tapered surface 19b of the packing 19 comes into contact with the seating surface 12 of the valve seat 11 as the spindle 13 is displaced, the spindle 13 closes the communicating hole 10. . On the other hand, when the operating member 17 is rotated around the axis of the spindle 13 in the opposite direction, the spindle 13 is separated from the valve seat 11 in the axial direction as shown in FIG. direction. As the spindle 13 is displaced, the tapered surface 19b of the packing 19 moves away from the seating surface 12 of the valve seat 11, thereby opening the communicating hole 10. As shown in FIG.

A mounting portion 21 for mounting a pressure gauge 20 for measuring the pressure in the pipe 3 is formed in a vertically extending portion of the body 2 below the partition wall 9 . As the pressure gauge 20, a differential pressure gauge for measuring the pressure inside the pipe 3 with reference to the atmospheric pressure is used. The mounting portion 21 has an upper end communicating with the pipe-side passage 7 and an open lower end so that the pressure gauge 20 can be mounted thereon. A connecting member 21a is attached to the opening side end (lower end) of the mounting portion 21, and the pressure gauge 20 is connected to the mounting portion 21 by the connecting member 21a. The inside of the mounting portion 21 always communicates with the pipe-side passage 7 regardless of how the communication hole 10 is opened or closed by the spindle 13 .

Next, leak inspection of the water supply and hot water supply system will be described.
When performing a leak inspection of a water supply and hot water supply system, first, the pipe connection port 4 of the body 2 of the leak inspection valve 1 is connected to the pipe 3 (connection member 3a) of the water supply and hot water supply system, and a pump for discharging the test fluid is operated. A hose 5 a (connection member 32 ) extending from 5 is connected to the pump connection port 6 of the body 2 . Furthermore, a pressure gauge 20 is attached to the attachment portion 21 of the body 2 . Thereafter, as shown in FIG. 2, the spindle 13 is displaced toward the valve seat 11 to bring the tapered surface 19b of the packing 19 into contact with the seat surface 12 of the valve seat 11 to close the communication hole 10, and in this state, the pump is operated. The inside of the pump-side passage 8 is filled with high-pressure test fluid by discharging the test fluid from 5 .

After filling the pump-side passage 8 with the high-pressure test fluid, the spindle 13 is displaced away from the valve seat 11 to open the communication hole 10, thereby allowing the test fluid in the pump-side passage 8 to flow through the communication hole. 10 and a pipe-side passage 7 into the pipe 3 of the hot water supply system. After the pipe 3 of the water and hot water supply system is filled with the high-pressure test fluid, the communication hole 10 is closed by the spindle 13 to seal the test fluid in the pipe 3 of the water and hot water supply system in a high pressure state.

After the test fluid is sealed in the pipe 3 of the hot water supply system in a high pressure state as described above, the connection member 32 (pump 5) is removed from the pump connection port 6 of the body 2 of the leak test valve 1. As shown in FIG. 3, the pump connection port 6 from which the connection member 32 has been removed is provided with a cap for blocking the pump connection port 6 and for preventing foreign matter from entering the pump connection port 6. A bottomed cylindrical plug 34 is inserted. Furthermore, a retaining member 33 is attached to the end of the body 2 where the pump connection port 6 opens to prevent the plug 34 from coming off from the pump connection port 6 .

In the leak test of the water supply and hot water supply system, the amount of pressure drop in the pipe 3 after a predetermined time has passed since the test fluid was sealed in the pipe 3 is measured using the pressure gauge 20, and the pressure drop amount is measured. is equal to or greater than a predetermined judgment value, it is determined that a leak has occurred in the water supply and hot water supply system.

Next, the shape of the packing 19 will be described in detail.
FIG. 4 shows the packing 19 provided on the spindle 13 in an enlarged manner. As can be seen from the figure, the length Xa of the cylindrical surface 19a of the packing 19 in the axial direction of the spindle 13 (vertical direction in FIG. 3) is greater than the length Xb of the tapered surface 19b of the packing 19 in the axial direction. has been too long. More specifically, the lengths Xa and Xb are set to values that satisfy the following equations “Xa=k·Xb (1)” and “1.82≦k<4.3 (2)”. It is In this embodiment, for example, a value of "3" is adopted as the coefficient k used in equation (1). Therefore, the relationship between the length Xa and the length Xb is "3:1".

Next, the action of the leak inspection valve 1 will be described.
In the leak test of the hot water supply system, the communication hole 10 of the leak test valve 1 is closed by the spindle 13 as shown in FIG. is filled with high pressure test fluid. At this time, the pressure of the test fluid acts on the packing 19 of the spindle 13. If the rigidity of the packing 19 away from the shaft portion 13a of the spindle 13 is low, the following problems may occur. be. That is, when the communicating hole 10 is opened by displacing the spindle 13 in order to supply the test fluid in the pump-side passage 8 into the pipe 3 , the part of the packing 19 away from the shaft portion 13 a of the spindle 13 is inside the pump-side passage 8 . There is a risk that the packing 19 will be deformed by the pressure from the test fluid, and that the packing 19 will come off from the shaft portion 13a accordingly.

However, in the packing 19, the length Xa of the cylindrical surface 19a in the axial direction of the spindle 13 is longer than the length Xb of the tapered surface 19b in the axial direction. The length in the axial direction of the portion away from the portion 13a is increased. As a result, the reduction in rigidity of the portion of the packing 19 away from the shaft portion 13a of the spindle 13 due to the formation of the tapered surface 19b on the packing 19 is suppressed. Therefore, when the communication hole 10 is opened by displacing the spindle 13 in the direction away from the valve seat 11 under the condition that the high-pressure test fluid is filled in the pump-side passage 8, the valve seat 11 side of the spindle 13 is opened. A portion of the packing 19 provided at the end portion away from the shaft portion 13a of the spindle 13 can be prevented from being deformed by the pressure from the test fluid.

According to this embodiment detailed above, the following effects can be obtained.
(1) It is possible to suppress the deformation of the packing 19 as described above, and it is possible to suppress the packing 19 from being detached from the shaft portion 13a due to such deformation.

(2) A step portion 11 a having an inner peripheral surface parallel to the center line of the communication hole 10 is formed at the upper end portion of the valve seat 11 . Therefore, when the communication hole 10 is closed by the spindle 13, even if the packing 19 hits the valve seat 11 and is crushed in the axial direction of the spindle 13 and is deformed so as to expand in the direction away from the coaxial line, such deformation is not caused by the stepped portion 11a. can be regulated by the inner peripheral surface of

(3) In the leak test of the hot water supply system, when the communication hole 10 is closed by the spindle 13 and the high-pressure test fluid is sealed in the pipe 3, the pressure measured by the pressure gauge 20 is lowered. The following causes [A] and [B] can be mentioned. [A] Leakage of test fluid in hot water supply system. [B] Leakage of test fluid from between the tapered surface 19b of the packing 19 and the seat surface 12 of the valve seat 11 in the leak test valve 1 .

Here, in the pressure drop due to the cause of [A] above, the pressure measured by the pressure gauge 20 continues to drop until the leakage point of the test fluid in the hot water supply system is blocked. On the other hand, in the pressure drop due to the above [B], since the pump connection port 6 of the body 2 is closed by the plug 34, the pressure drop measured by the pressure gauge 20 is measured by the tapered surface of the packing 19. 19b and the seating surface 12 of the valve seat 11 fills the space in the pump-side passage 8 and the plug 34 with the leaked test fluid, and stops. In other words, the pressure measured by the pressure gauge 20 drops due to the leak, but stops after a certain amount of such pressure drop.

Therefore, when the pressure measured by the pressure gauge 20 in the leak test decreases by closing the pump connection port 6 of the body 2 with the plug 34 as described above, is it due to the above [A]? Alternatively, it is possible to determine whether it is due to the cause of [B] above based on the manner in which the pressure is lowered. Therefore, regardless of whether or not the test fluid leaks from between the tapered surface 19b of the packing 19 and the seat surface 12 of the valve seat 11, whether or not the leak occurs in the hot water supply system is determined as described above. Accurate determination can be made based on the state of pressure drop.

It should be noted that the above embodiment can be modified, for example, as follows.
-Although the value "3" was exemplified as the coefficient k used in the above formula 1, the coefficient k may be changed as appropriate within the range of "1.82 ≤ k <4.3" shown in formula (2). .

- In the leak test valve 1, the pressure gauge 20 is connected to the body 2 to measure the pressure of the test fluid in the pipe 3, but adopting such a structure is not essential. For example, while the pressure gauge 20 is connected to the pipe 3 or the like of the hot water supply system to be inspected and the pressure in the pipe 3 is measured, the pressure gauge 20 such as the mounting portion 21 is attached to the body 2 of the leak inspection valve 1. You may make it remove the structure for.

The pump connection port 6 in the body 2 of the leak inspection valve 1 does not necessarily have to be closed with the plug 34 .
- It is also possible to use a liquid such as water instead of a gas such as air as the inspection fluid for leak inspection.

DESCRIPTION OF SYMBOLS 1... Leak inspection valve, 2... Body, 3... Piping, 3a... Connecting member, 4... Piping connection port, 4a... Connecting member, 5... Pump, 5a... Hose, 6... Pump connection port, 7... Piping Side passage 8 Pump-side passage 9 Partition wall 10 Communication hole 11 Valve seat 11a Stepped portion 12 Seat surface 13 Spindle 13a Shaft 14 Accommodating portion 15 Male thread 16 Female thread member 17 Operation member 18 Seal ring 19 Packing 19a Cylindrical surface 19b Tapered surface 20 Pressure gauge 21 Mounting portion 21a Connecting member 31 Connecting member , 32... Connecting member, 33... Retaining member, 34... Plug.

Claims (1)

A body having a pipe connection port connected to a pipe to be inspected and a pump connection port to which a pump that discharges a test fluid is connected, a pipe-side passage connected to the pipe connection port and the pump connection port. A partition wall is formed to partition the connected pump-side passage, and the partition wall is formed with a communication hole connecting the pump-side passage and the pipe-side passage, and a valve seat surrounding the communication hole. A spindle for opening and closing the communication hole is provided in the body so as to be displaceable in the axial direction. In the leak inspection valve in which the communication hole is opened and closed,
The end of the spindle on the side of the valve seat is attached to the end by penetrating a shaft integrally formed at the end, and the tip of the shaft is integrally formed with the tip. A packing is provided that is prevented from coming off from the shaft portion by making it larger in diameter than the other portions,
The packing has a cylindrical surface that is parallel to the axis of the spindle and a diameter that decreases from the valve seat side end of the cylindrical surface toward the valve seat side of the spindle. a tapered surface that contacts the valve seat through displacement to
A leak inspection valve, wherein the length of the cylindrical surface in the axial direction of the spindle is longer than the length of the tapered surface in the axial direction.

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