JPH0469744B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications.

The present invention relates to a hydraulic pressure testing method for sleeve-type couplings used in pressure-generating pipes such as water turbines, pump-turbines, and pumps.

PRIOR TECHNOLOGY In pipes with pressure such as water turbines, pump water turbines, pumps, etc., a large restraining force is generated on the pipes due to thermal expansion, deformation, or ground movement relative to the surroundings where the pipes are installed. Therefore, the difference in expansion between the pipe and the supporting ground is relieved by cutting the pipe at key points and installing couplings that allow relatively large movement. An example of such a coupling is shown in FIG. That is, in the creep type coupling 21, after the sleeve 1 presses the gasket 3 provided around the outer periphery of each of the upstream short pipe 5 and the downstream short pipe 6, a gasket presser is attached to each outer end of the gaskets. A ring 2 is installed, and then both rings are tightened at multiple points with gasket holding bolts and nuts 4. In order to confirm the pressure resistance strength and soundness against leakage, the pipe line is Before its use, it is necessary to perform a water pressure test that applies water pressure higher than the normal pressure, and if the sleeve is to be subjected to a water pressure test, both ends of the sleeve must be closed with watertight lids, and the pipe diameter is large. In this case, the watertight lid must also be constructed to be significantly larger, which poses problems in manufacturing costs and handling.

In response to this, the inventor made a proposal described in Japanese Patent Publication No. 57-43854 in order to reduce costs and labor. That is, the third
In Figures a and 3b, the upstream short pipe 5 and the downstream short pipe 6 are integrally manufactured to form an upstream and downstream short pipe, and the upstream and downstream short pipes are arranged so that pressure acts on the inside of the sleeve 1 of the sleeve type coupling 21. Several through holes 10 are drilled at the cutting positions, and water pressure covers 8 and 9 are provided at both ends of the upstream and downstream short pipes, respectively, and then from the water supply hole 11 drilled in one of the water pressure covers. By filling with pressure water, the pressure of the pressure water is applied to the inner surface of the sleeve at the same time as the upstream and downstream short pipes, thereby improving the integrity of the upstream and downstream short pipes and the coupling as a whole. After confirmation, the coupling is completed by cutting the upstream and downstream short pipes at the positions of the through holes 10 to form the upstream short pipes 5 and downstream short pipes 6 shown in FIG. It is.

As mentioned above, the inventor's previous proposal has made the water pressure test of the sleeve type coupling 21 extremely easy to perform, but leakage occurred in the coupling part during the water pressure test and some modification was required. When construction is necessary, the pressure water in the upstream and downstream short pipes must also be discharged, and if the pipes before and after the coupling are long, a large amount of water must be supplied and discharged. For example, there are cases where a large amount of water reaches 6,000 cubic meters, and repeating the pouring and draining of such a large amount of water inevitably has the disadvantage that the usefulness of the existing proposal is considerably impaired.

Problems to be Solved by the Invention The present invention eliminates the need to drain a large amount of water from the upstream and downstream short pipes when modifying the coupling part during a hydraulic test of a sleeve type coupling, and reduces testing costs. The aim is to shorten the construction period.

Means for Solving the Problems The present invention provides a sleeve of a sleeve-type coupling ring installed over the periphery of the upstream and downstream short pipes to be cut after a water pressure test, each of which has both ends closed with watertight lids, and the upstream and downstream short pipes. A water pressure test is performed by injecting pressurized water through the water supply holes drilled in each of the watertight lids on one side of the sleeve, and then the short pipe is cut, both watertight lids are removed, and the water supply holes in the sleeve are blocked. The structure is constructed so that each of them is constructed separately.

Effects Therefore, according to the configuration of the present invention, it is possible to simultaneously carry out hydraulic pressure tests on upstream and downstream short pipes and sleeve type couplings, and if the sleeve,
Alternatively, even if it is discovered that there is a defect in the gasket, it is only necessary to drain the injected water from that part and carry out repair work, eliminating the need to drain a large amount of water in the upstream and downstream short pipes. Since the same pressure acts on the inner and outer peripheries of the upstream and downstream short pipe sections surrounded by the pipe, and there is no pressure difference, there is no need to maintain pressure resistance in the short pipe section. The configuration will be simple.

Embodiment Next, an embodiment of the present invention will be explained with reference to the drawings. In FIG. After the fabricated upstream and downstream short pipes 7 are subjected to a water pressure test, they are cut to form the upstream short pipes 5 and downstream short pipes 6. From the sleeve 1, the gasket holding ring 2, the gasket 3, and the gasket holding bolt nut 4, A water supply hole 22 is provided in the watertight lid 8, and another water supply hole 23 is provided in the sleeve 1, and a water supply pipe 15 and 13 is provided in each of the water supply holes. and connecting both water supply pipes to the water pressure test water supply pump 16,
Next, in the sleeve type coupling water pressure test mechanism in which a water pressure gauge 12 is attached to the water supply pipe 15 and a three-way valve 14 is attached to the water supply pipe 13, first, the external communication port 17 of the three-way valve is attached.
After closing, the water supply pump 16 is operated to supply pressure water from the water supply pipe 15 to the upstream and downstream short pipes 7, and from the water supply pipe 13 to between the short pipes and the sleeve 1, and monitor the water pressure gauge 12. Perform a water pressure test by injecting water while maintaining the desired pressure,
After confirming that there are no areas to be revised,
Both water supply pipes are all removed, the upstream and downstream short pipes 7 are cut at predetermined positions, and both watertight lids 8 are removed.
and 9, and further remove water supply hole 2 of sleeve 1.
3 is occluded. If there is water leakage in the coupling and repair work is required,
Alternatively, when testing a short pipe section surrounded by the sleeve, the desired purpose can be achieved by draining only the inside of the sleeve 1 using the three-way valve 14, thereby draining a large amount of water from inside the short pipe. There is no need to discharge it at all. As shown in FIG. 2, since the upstream short pipe 5 and the downstream short pipe 6, which are connected by the sleeve type coupling 21 according to the present invention, move relative to each other, the gasket 3 does not move during the water pressure test.
Something that was inside the sleeve may be placed outside and receive pressure. In such a case, if it is anticipated, it is desirable to also perform a water pressure test on the short pipe inside the sleeve. When the external communication port 17 is opened to the atmosphere in order to discharge the water in the water supply pipe 13 from the valve 14, a pressure difference is also applied to the short pipe inside the sleeve, so if water leaks, the water supply pipe 13 Since leakage occurs after passing through the tube, it is also possible to confirm the pressure-resistant soundness of the portion of the short tube surrounded by the sleeve. Furthermore, the first
In the coupling hydraulic test mechanism shown in Figure a, parts that are installed in the piping system for normal pressure tests, such as air vent valves and safety valves, are not shown, but these are not directly related to the explanation of the water pressure test method according to the present invention. Therefore, illustration and explanation are omitted.

Next, instead of the three-way valve of the water pressure test mechanism described above, a stop valve 1 is installed in the water supply pipe 15 as shown in FIG. 1b.
8, or by attaching a stop valve 19 to each of the water supply pipes 13 and attaching a stop valve 20 to a branch pipe from the water supply pipe 13 so that the water can be freely opened to the atmosphere and drained, the effect of the present invention is still the same as described above. It goes without saying that it is exactly the same as the embodiment.

Effects of the Invention As described above, the present invention can reduce the cost and shorten the construction period for coupling water pressure tests, and also eliminates the need to discharge large amounts of water supply from upstream and downstream short pipes when modifying the coupling part. It has great industrial utility value.

[Brief explanation of the drawing]

FIG. 1a is a longitudinal cross-sectional side view of the main part of a coupling hydraulic pressure test mechanism according to an embodiment of the present invention, and FIG.
The figure is a longitudinal side view of the main part showing another embodiment, Fig. 2 is a longitudinal side view showing an example of a sleeve type coupling, and Fig. 3a is a cross-sectional side view of a conventional coupling hydraulic test method according to an existing proposal. A longitudinal side view showing,
FIG. 3b is a sectional view taken along line B-B of the previous figure. DESCRIPTION OF SYMBOLS 1...Sleeve, 2...Gasket holding ring, 3...Gasket, 4...Gasket holding bolt nut, 5...Upstream side short pipe, 6...Downstream side short pipe, 7...Upstream and downstream short pipe according to the present invention Tube, 8, 9...
...Watertight lid, 10...Through hole, 11...Water supply hole,
12... Water pressure gauge, 13... Water supply pipe, 14... Three-way valve, 15... Water supply pipe, 16... Water supply pump, 1
7... External communication port, 18, 19, 20... Stop valve, 21... Sleeve type coupling, 2
2, 23...Water supply hole.

Claims (1)

[Claims] 1. A blind cover is provided at both ends of the short pipe to be cut after the test, and a sleeve type coupling joint is set on the circumference of this short pipe, and a sleeve type coupling joint is provided on the blind cover and the sleeve of the sleeve type coupling joint, respectively. A water pressure test is performed on the short pipe and the sleeve type coupling joint by injecting pressurized water from the water supply hole, and then the short pipe is cut, the blind cover is removed, and the water supply hole of the sleeve is closed to form the sleeve type coupling joint. A hydraulic test method for sleeve-type cut-up rings, which is characterized by completing the ring.