JP3058587B2 - Leak test equipment for piping etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak test apparatus for piping and the like, and more particularly, to pressurizing water or the like filled in a test pipe to a predetermined pressure by a pressurizing pump operated by an electric motor. A leak testing device for a pipe or the like for testing the leak of a test pipe, for pulsating pressure that generates pulsating pressure in the test pipe by repeating opening and closing when connected to the test pipe under pressure. The present invention relates to a leak test device for piping and the like including an on-off valve.

[0002]

2. Description of the Related Art Construction conditions at joints of various pipes (air-conditioning, plumbing pipes, etc.) of buildings and the like and connections with various devices, that is, poor insertion of piping materials and tightening of the joints (connections). Conventionally, a leak test (pressure test) has been performed for each piping site or each piping system in accordance with the progress of piping work for inspection of defects and the like. For such inspection, water is usually filled in the test pipes by a manual pressurized pump or a pressurized pump operated by an electric motor, or the water filled in the test pipes is filled with water by these pressurized pumps. The pressure is increased to a predetermined pressure (static pressure) in accordance with the pressure and maintained for a certain period of time to determine whether or not the pressure has decreased.

[0003] On the other hand, even in a pipe determined to be "good" because there is no pressure drop in such a static pressure test, the pipe is connected to the pipe in a relatively short period of time when the building is completed and the use of the pipe is started. Problems such as leakage may occur. The reason is that although hydrostatic pressure does not lead to leakage, in the actual use of pipes, various pressure fluctuations are repeatedly applied in the pipes, so that loose connection occurs at the poor connection part of the pipe, as a result, It is considered that there is a high risk of leakage from the beginning of the construction, so to say, a potential defective part causes water leakage.
As described above, a leak test using static pressure alone is not sufficient as a test.In recent years, instead of the test, a pulsating pressure accompanied by pressure fluctuations similar to actual use has been applied to prevent poor connection of piping. To promote the degree, to reveal the potential defective part of the pipe joint, and to apply such a pulsating pressure, then actively detect the defect by conducting a static pressure test Various leak testing devices for pipes (piping leak testing devices) have been developed.
It has also been put to practical use.

[0004] One example is disclosed in JP-A-59-1607.
There is a technique described in JP-A-33-33. In addition to a pressurizing means (pump) which is connected to the test pipe and increases the pressure in the pipe, a branch which branches off the outlet side of the pressurizing means and returns to the water storage tank. Path (branch pipe), an on-off valve (a solenoid valve or an electric valve) provided in the branch path,
An opening / closing drive mechanism such as a timer that alternately opens and closes the opening / closing valve at a predetermined cycle.

In this apparatus, the outlet side of the pressurizing means is connected to a test pipe, and the open / close valve is operated at a predetermined cycle by an open / close drive mechanism while the inside of the test pipe is pressurized to a predetermined pressure. A pulsating pressure is generated by repeatedly opening and closing the pressure. In other words, when the on-off valve is in the open state, water is discharged to the outside, so that the pressure is rapidly reduced, and when the on-off valve is in the closed state, the pressure is rapidly increased. Pulsating pressure is generated to promote the degree of poor connection of the pipe, water is leaked from a potential defective portion of the connection, and a defective connection of the pipe is positively found.

[0006]

In the generation of pulsating pressure by such a technique, a necessary pressure difference (lower limit pressure) is required if the opening time is too short while the on-off valve is repeatedly opened and closed at a constant cycle. Therefore, it is not possible to positively loosen the joint to the poor joint of the pipe. On the other hand, if the valve opening time is too long, although the pressure is greatly reduced, the pulsation cycle becomes longer, so that a longer test time is required, and the test becomes inefficient. Further, in order to effectively promote the degree of poor connection of the pipe and find a potential defective portion, it is necessary to apply a pulsating pressure a predetermined number of times or more. For this reason, when pulsating pressure is applied, it is necessary to appropriately set the opening time of the on-off valve and its cycle in order to generate the pulsating pressure. Need to do.

However, in the above-mentioned prior art, an electromagnetic valve or a motor-operated valve is required as an on-off valve for generating pulsation, and the valve opening time and cycle are controlled by an on-off drive mechanism such as a timer provided separately from the pressurizing pump. It is configured to be set by That is, since a predetermined pulsating pressure is generated by adjusting the opening time and cycle of the on-off valve according to the test pipe, the setting is troublesome. Moreover, while the set valve opening time and the like vary depending on the person in charge of the test operation, the test conditions tend to be inappropriate due to the difference in these set values. In other words, in the above-described conventional technology, the effect of promoting the degree of poor joining may not be sufficiently obtained, and is found during the test or in a pipe leak test (hydrostatic pressure test) performed thereafter. There was a problem that a potential defective part to be found could not be found.

The present invention has been made in view of such problems of the prior art, and has as its object to provide a solenoid valve or a motor-operated valve for generating pulsating pressure, and a timer or the like. It is an object of the present invention to provide a device that can easily perform a pulsation pressure test based on a predetermined valve opening time and cycle set in advance without requiring an opening / closing drive mechanism.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a pressurizing pump operated by an electric motor to pressurize water or the like filled in a test pipe to a predetermined pressure. A leak testing device for a pipe or the like for testing the leak of a test pipe, for pulsating pressure that generates pulsating pressure in the test pipe by repeating opening and closing when connected to the test pipe under pressure. In an apparatus provided with an on-off valve, the pulsating pressure on-off valve is configured to be opened or closed by reciprocating a valve rod provided on the valve body in an axial direction, and the valve body is provided with: While being biased by a spring member so as to be normally kept closed, a reduction shaft is connected to a rotation shaft of the electric motor via a reduction mechanism, and a cam is fixed to the reduction shaft. So that the valve element is opened by the rotation of A structure for moving the serial valve rod, characterized by being configured to repeatedly open and close at a predetermined period.

When using the above-mentioned means, the outlet side of the pressurizing pump is connected to the test pipe so as to be pressurized, while the test pipe and the pulsating pressure on-off valve are separated from each other. The valve is piped through a manual on-off valve (hereinafter referred to as a pulsation test on-off valve), and the pulsation test on-off valve is kept closed to maintain a constant pressure in the test pipe. Activate the pressure pump to hold. The pressure control valve may be provided on the pressurizing pump or on the test pipe side.

[0011] Under the operation of the pressurizing pump, the valve of the pulsating pressure on-off valve repeatedly opens and closes at a constant period for each rotation of the cam. At this time, if the separate pulsation test on-off valve is held in the open state, water in the pipe under test causes the pulsation test on-off valve and the pulsation pressure on-off valve to open while the pulsation pressure on-off valve is open. When the pressure is rapidly reduced due to being discharged to the outside and the valve is closed, the discharge is stopped and the pressure is rapidly increased by the operation of the pressure pump. Thus, only by holding the pulsation test on-off valve in the open state, a constant pulsating pressure is repeatedly applied to the test pipe by a predetermined period and valve opening time.

By applying this pulsating pressure for a predetermined period of time, the degree of poor connection of the pipe is promoted, so that the sealing state of a potential defective portion of the connected portion is likely to be lowered or destroyed. Can be done. Then, if necessary, after this, while maintaining the pulsation test on-off valve in the closed state, the pressurizing pump is operated to apply a constant static pressure to the test pipe in the same manner as before, and the test pipe system is operated. Is held in a closed state, and the presence or absence of a decrease in pressure after a lapse of a predetermined time is examined, whereby the existence of a potential defective portion can be known.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a leak test apparatus for pipes and the like according to the present invention will be described in detail with reference to FIGS. FIG. 1 shows the main components of a leak test apparatus such as a pipe. An electric motor 1 is fixed on a base (not shown), and a known plunger type actuated by its rotation is provided on its rotating shaft 2 side. Is mounted. The pressurizing pump 3 is a well-known pump, and is not shown in detail. is there. In FIG. 1, a predetermined joint 8 is connected to the inlet 7 side of the pressurizing pump 3, and through this joint 8, as shown in FIG. T water is sucked, and the outlet 10
A predetermined joint 11 is also connected to the side, and a test pipe K is connected via a pipe 12 and a predetermined opening / closing valve 13. In FIG. 2, the range indicated by the two-dot chain line indicates the leak testing device for piping and the like of this example.

That is, as shown in the piping system diagram of FIG. 2, the leak test apparatus for piping and the like of the present embodiment is connected to the outlet 10 of the pressurizing pump 3 operated by the electric motor 1 through the T pipe joint 11. A pipe 12 is provided, and water can be supplied to the test pipe K via a pressure gauge 14 and an on-off valve 13 for connecting the test pipe. The vicinity of the pressure gauge 14 is branched by a T pipe joint and connected to a pulsation pressure on-off valve described below via a pulsation test on-off valve (in this example, a manual ball valve) 15 and a pipe 16. Further, a pipe 12 connected from the outlet 10 of the pressurizing pump 3 to the test pipe is branched so as to return to the tank T side, and a pressure regulating valve (relief valve) 17 is provided in the middle of the pipe. It is provided so that the inside of the test piping system is maintained at a set pressure.

Next, a description will be given of a pulsating pressure on-off valve which is an essential part of the present invention. In FIG. 1, reference numeral 21 denotes a pulsating pressure on-off valve of the present embodiment, and as shown in FIGS.
2, a test pipe connection port 23 and a discharge port 24 connected to the test pipe side are provided on the right side of FIG.
5 is provided so as to be able to slide (slide) left and right along a bearing 27 in the axial direction along a valve stem 26 provided therein.
In the present example, the hole of the flange 28 with a screw hole fixed to the valve box 22 forms the test pipe connection port 23. Reference numeral 29 denotes a seal packing so that water in the valve box 22 does not leak to the outside even when the valve stem 26 slides. A spring member (compression coil spring in this example) 31 is interposed between the valve body 25 and the bearing 27 on the outer periphery of the valve stem 26, and a valve seat inside the test pipe connection port 23 is provided. The valve element 25 is constantly pressed against the spring 32 by the urging force of the spring member 31 to maintain the valve closed state. In FIG. 3, a 90-degree elbow (joint) 33 is screwed into the test pipe connection port 23, and a nipple 34 is screwed into the discharge port 24. The pipe 16 is connected to the pulsation test on-off valve 15. The nipple 34
Is connected to a tube 35 to return water to the tank T (see FIG. 2).

On the other hand, the base end side (the left side in FIGS. 3 and 4) of the valve stem 26 penetrates the valve box 22 via a seal packing, and a rectangular frame 41 is integrally formed at the end. And is arranged so as to slide right and left together with the valve stem 26. However, in the frame 41, a T-shaped member 42 and a U-shaped member 43 screwed to the valve stem 26 are integrated via a screw member 44. Inside the frame 41, the above-described eccentric pinion 4 also serving as a shaft coupling and a reduction gear (reduction mechanism) 45 are provided on the rotation shaft 2 (output shaft) of the electric motor 1 for operating the pressurizing pump 3. Reduction shaft 46 provided continuously
Are arranged in a state of being stopped by a pair of bearings 47, 47, and a cam (a tangential cam in this example) 51 is fixed to an end thereof. In this example, the rotating shaft 2, the distal end side shaft portion 4a of the eccentric pinion 4 serving also as a shaft coupling, and the deceleration shaft 46 are provided coaxially.

When the valve body 25 is pressed against the valve seat 32 of the test pipe connection port 23 and is closed, the cam 51 of this embodiment is closed.
In order to ensure that the valve is closed, it is formed and arranged so as not to contact the frame 41. On the other hand, when it rotates, in this example, it collides with one side (FIG. 3, 4 left) 43a of the frame body 41 in a sliding contact state for about 1/4 rotation during one rotation, and the valve stem 26 In the figure, the valve body 25 is slid to the left to separate the valve body 25 from the valve seat 32 by a predetermined amount to open the valve against the urging force (spring force) of the spring member 31. That is, in this example, approximately one-fourth of the rotation of the cam 51 (reduction shaft) is performed.
During rotation, the valve is opened, and the fluid is allowed to pass from the test pipe connection port 23 to the discharge port 24 as shown by the arrow in FIG. 4, and the valve is closed and cut off during other times. It is configured to:

The reduction gear (reduction mechanism) 45 of this embodiment is
The reduction shaft 46 to which the cam 51 is fixed is connected to the rotation shaft 2 of the electric motor 1.
And three speed reducers (planetary gear units) 45 arranged in series so as to coaxially reduce the speed.
2. The gear box 52 is fixed to a base (not shown) of the leak test device for piping or the like of the present embodiment via a flange 53. In this example, the cam device is covered by a casing 54 integrally formed from the valve box 22, and the casing 54 is fixed to the gear box 52. In this example, as shown in FIG. 4, guide set screws 55, 5 for sliding the frame 41 are provided substantially at the center of the upper and lower outer sides of the casing 54.
5 is screwed.

Thus, as shown in FIG. 2, the test pipe connection port 23 of the pulsation pressure on-off valve 21 and the pulsation test on-off valve 1
5 and the inside of the test pipe K can be pressurized through the test pipe connection on-off valve 13 to perform a test as follows. However, the pulsation test on-off valve 15 is kept closed.

That is, the electric motor 1 is driven to operate the pressurizing pump 3 to supply water into the test pipe K to fill the pipe, or pressurize the water previously filled in the test pipe K, The inside of the system is maintained at a fixed set test pressure (pulsation upper limit pressure) by the pressure adjusting valve 17. At this time, the pulsating pressure on-off valve 2 of this example
The first cam 51 rotates at a predetermined number of revolutions via the rotating shaft 2 of the electric motor 1 and the speed reducer 45, and the frame 41 and the valve rod 26 repeatedly reciprocate left and right at a constant cycle for each rotation. The valve body 25 is repeatedly opened and closed.

Therefore, when the pulsation test on-off valve 15 is kept open under this condition, the pulsation pressure on-off valve 21 of this embodiment repeatedly opens and closes at a constant cycle for each rotation of the cam 51.
The water in the test pipe K is spouted momentarily from the discharge port 24 side,
Then, the pressure is stopped, and a pulsating pressure is generated by the rapid decrease and rapid rise of the pressure due to the repetition. That is, according to the present example, the depressurization and the pressurization are alternately repeated in accordance with the opening and closing, and during this time, the pulsating pressure under the constant conditions according to the predetermined cycle and the valve opening time is continuously applied to the test pipe K. In such a case, it is sufficient to see the water leakage during that time.

If necessary, after a lapse of a predetermined time (the number of pulsation tests), the pressurizing pump 3 is operated to connect the sample pipe K with the pulsation test on-off valve 15 held in the closed state. A predetermined (constant) water pressure is applied, the on-off valve 13 for connection of the test pipe is kept closed, the test pipe K is closed, and the operation of the pressurizing pump 3 is stopped. Then, after a lapse of a predetermined time, the presence or absence of a pressure drop in the test pipe K may be checked, and the presence or absence of water leakage may be checked. In this example, the pulsation pressure test and the static pressure (constant pressure) test can be easily switched only by opening and closing the pulsation test on-off valve 15, so that the static pressure test is performed following the pulsation pressure test. Since the test can be performed simply and quickly, the test can be performed very efficiently.

The reduction mechanism of the present invention rotates the rotation shaft 2 of the electric motor 1 at a reduction ratio (the number of rotations of the cam) at which the reduction shaft 46 to which the cam 51 is fixed is at a desired valve opening cycle. What is necessary is just to be able to decelerate quickly, and it is sufficient to design it appropriately with a gear device or the like. Further, in the above-described embodiment, the mechanism is a mechanism for decelerating coaxially. However, the present invention is not limited to such a mechanism, and a mechanism for decelerating on a staggered shaft may be used. Further, in the above-described embodiment, the tangential cam is used as the cam 51; Should be designed.

The connection port or discharge port on the test pipe side in the pulsating pressure on-off valve is a relative one.
Discharge port 24 and pulsation test on-off valve 15 in the above example
Can be connected so that water can be discharged from the test-pipe-side connection port 23. In this example, the pressure control valve 17 is provided in a leak test device such as a pipe, but may be provided in any pipe system for a pulsation test as described above. It is clear that the leak test device for pipes and the like according to the present invention can be tested with fluids other than water and air.

Embodiment 2 Next, Embodiment 2 according to the present invention will be described with reference to FIG. 5. In this embodiment, the pulling force acts on the valve stem 26 when the valve is opened in the previous embodiment. In this embodiment, a compressive force acts on the structure. That is, in the previous example, the valve is opened by moving the valve body 25 to the left in the drawing, but in the present example, the valve is opened by moving the valve 25 to the right. Then, since it is basically the same as the previous example, the description will focus on the differences.

In FIG. 5, reference numeral 121 denotes a main part of the pulsating pressure on-off valve of the present embodiment, and as shown in FIG.
2, a test pipe connection port 123 and a discharge port 124 connected to the test pipe side are provided on the right side of FIG. It is provided so as to be slidable (slidable) right and left along 127. In this example, the hole of the flange 128 with a screw hole fixed to the valve box 122 is
I am doing. Reference numeral 129 denotes a seal packing so that water in the valve box 122 does not leak to the outside even when the valve stem 126 slides. In FIG. 5, as in the previous example, a 90-
The elbow (joint) 133 is screwed, and the discharge port 12
A nipple 134 is screwed into the nipple 4, and a 90-degree elbow 133 is connected to a pulsation test on-off valve (not shown) through a pipe 116.
Is connected to a tube 135 for returning water to a tank (not shown).

On the other hand, the base end side of the valve stem 126 (the left side in FIG. 5).
Is penetrated through the valve box 122 via a seal packing, and a rectangular plate 141 is integrally fixed to an end portion thereof, and is disposed so as to slide right and left together with the valve stem 126. However, on the outer periphery of the valve stem 126 and between the rectangular plate 141 and one side surface 122a of the valve box 122,
A spring member (compression coil spring in this example) 131 is interposed, and the valve body 25 is constantly urged to the left side in FIG. 5 by the urging force of the spring member 131 on a valve seat 132 formed in the valve box 122. And is configured to hold the valve closed state.

On the left side of the rectangular plate 141, a reduction shaft 146, which is continuously provided in the same manner as in the previous example, is disposed in a state of being fixed by a pair of bearings (not shown). The same cam 151 as the previous example is fixed. Also,
The cam 151 of this example is also formed and arranged so as not to contact the rectangular plate 141 as in the previous example, in order to ensure that the valve is closed when the valve body 125 is pressed against the valve seat 132 and closed. Have been.

In this embodiment, when the cam 151 rotates, it slides on one main surface (the left side in FIG. 5) of the rectangular plate 141 for approximately 1/4 rotation during one rotation as in the previous example. In the contact state, the valve rod 126 is slid against the urging force (spring force) of the spring member 131 to the right in FIG.
5 is opened a predetermined distance from the valve seat 132. That is, in this example, approximately one-fourth of the rotation of the cam 151 is performed.
During rotation, the valve is opened, and the fluid can pass from the test pipe connection port 123 to the discharge port 124 as shown by the arrow in FIG. It is configured to:

As described above, the present embodiment is different only in that the valve is opened by moving the valve stem 126 to the right, and the operation or effect is the same as that of the previous example. I do.

[0031]

According to the leak testing apparatus for pipes and the like according to the present invention, the means for generating the pulsating pressure, that is, the opening of the pulsating pressure on-off valve, is reduced to the rotating shaft of the electric motor as the operating means of the pressurizing pump. A deceleration shaft is continuously provided through a mechanism, and a cam is fixed to the deceleration shaft. The cam is rotated by rotating the cam. No opening / closing drive mechanism such as a valve and a timer is required. In addition, a pulsating pressure test can be easily performed with a predetermined period and valve opening time without requiring any special operation. Therefore, it is possible to efficiently and stably perform the pulsating pressure test under a certain condition that has an effect of appropriately promoting the degree of poor joining. Furthermore, according to the apparatus according to the present invention, since the test conditions are standardized, it is also effective in preventing oversight of a potential defective portion due to variation in the conditions of the pulsation test, and a piping defect such as water leakage is provided. This is effective for preventing (trouble).

[Brief description of the drawings]

FIG. 1 is a plan view showing main components of a first embodiment of a leak test apparatus for piping and the like according to the present invention.

FIG. 2 is a piping diagram illustrating the piping diagram of FIG. 1 and how to use it.

FIG. 3 is an enlarged view of a main part (on / off valve for pulsating pressure) of FIG. 1;

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

FIG. 5 is a cross-sectional view illustrating a pulsating pressure on-off valve according to a second embodiment of the leakage test apparatus for piping and the like according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 2 Rotary shaft of electric motor 3 Pressurizing pump 21, 121 Pulsating pressure on-off valve 25, 125 Valve body 26, 126 Valve rod 31, 131 Spring member 45 Reduction gear (reduction mechanism) 46, 146 Reduction shaft 51, 151 Cam K Test piping

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Kobayashi 3-60 Kamiida Nishimachi, Kita-ku, Nagoya-shi Asada Co., Ltd. (72) Inventor Toshihisa Matsushima 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Takashi Takahashi Kashima Construction Co., Ltd. 1-2-7 Moto-Akasaka, Minato-ku, Tokyo (72) Inventor Akio Sanbon 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Yoshio Kaihobo 3-6-18, Shibaura, Minato-ku, Tokyo Inside Nishihara Sanitary Industry Co., Ltd. (56) References JP-A-59-160733 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/26 G01M 3/00

Claims (1)

(57) [Claims] 1. A leak test apparatus for a pipe or the like for testing a leak in a test pipe by pressurizing water or the like filled in the test pipe to a predetermined pressure by a pressurizing pump operated by an electric motor. A pulsating pressure on-off valve for generating pulsating pressure in the test pipe by repeating opening and closing when connected to the test pipe under pressure, wherein the pulsating pressure on-off valve is The valve rod provided on the valve element is reciprocated in the axial direction to open or close the valve, and the valve element is urged by a spring member so that the valve element is always kept closed. On the other hand, a reduction shaft is connected to the rotation shaft of the electric motor via a reduction mechanism, and a cam is fixed to the reduction shaft, and the valve stem is opened by rotation of the cam. , And open and close repeatedly at regular intervals A leak testing device for piping and the like, characterized by having a configuration.