JP2000074779A - Dynamic pressure test method for of prefabricated piping unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dynamic pressure test of a prefabricated piping unit to provide certainty of a water leakage inspection of the unit. SOLUTION: A dynamic pressure tester 6 is connected to the inlet side end of a main pipe 1, and a hose 8 with a valve 7 is connected to the front end side end of each branch pipe 2. Then, the valve 7 is opened, water is filled from the tester 6 in the pipe 1 and the pipe 2, and the respective pipes are air bled. Thereafter, the valve 7 is closed, an operation for urging the water from the tester 6 to the pipe 1 and the pipe 2 and an operation for drawing the water from the pipe 1 and the pipe 2 are alternately repeated many times. Thus, pressure changes are given to the pipe 1 and the pipe 2, and hence the detection of a fault such as a fusion bonding fault or the like can be effectively and easily conducted as compared with the case of merely continuously applying a hydrostatic pressure thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prefabricated piping unit in which a main pipe made of a flexible resin pipe and a branch pipe are fusion-bonded at a factory before shipment due to defective fusion of the prefabricated piping unit. The present invention relates to a dynamic pressure test method for detecting a water leakage point and the like.

[0002]

2. Description of the Related Art For the purpose of streamlining and labor-saving piping work for water supply / drainage equipment installed in a house or the like, a main pipe and a branch pipe made of a flexible resin pipe are jointed or headered in advance in a factory. A prefabricated piping unit has been proposed which is joined by heat fusion via a pipe.
No. 78, Japanese Unexamined Patent Publication No. 5-172287, etc.). Before the prefabricated piping unit is shipped, it is subjected to an air (air pressure) test (for example, 6 kgf / cm ² × 10 minutes) and a water pressure test (for example, 10 kgf / cm ² × 30) in addition to appearance and dimensional inspection as quality inspection. Minutes)
Detection of a water leak location is performed.

[0003]

However, in an inspection in which only air pressure or water pressure (static pressure) is continuously applied, there are defective fusion spots where water leakage may occur due to excessive or insufficient heating of the heat fusion portion. Sometimes could not be detected.

An object of the present invention is to provide a dynamic pressure test method for a prefabricated piping unit which can easily and reliably detect a defective portion such as defective fusion.

[0005]

According to the present invention, there is provided a prefabricated piping unit in which a main pipe made of a flexible resin pipe and a branch pipe are joined in advance by heat or electric fusion via a joint or a header at a factory. A dynamic pressure test method, wherein a dynamic pressure tester is connected to the inlet end of the main pipe, a hose with a valve is connected to the distal end of each branch pipe, and then the valve is opened, and the dynamic pressure test is performed. A step of filling the main pipe and the branch pipe with water from the machine to bleed air from each pipe, and then alternately performing an operation of closing the valve, pushing water from the dynamic pressure tester into the main pipe and the branch pipe, and extracting the water. And a process that is repeated a number of times.

[0006] The operation of pushing water into and pulling out water from the main pipe and the branch pipe is performed at a pressure difference of 10 kgf / cm ² or more by 10 to 30 times.
Performed 0 times. After the dynamic pressure test, the valve is opened, the dynamic pressure tester is removed from the inlet side end of the main pipe, and air is sent into the main pipe and the branch pipe to drain water.

[0007]

When the main pipe and the branch pipe are joined by heat fusion or electric fusion, especially in the case of the fusion joining of the main pipe and the branch pipe having a small diameter, an abnormal operation called overheating causes the inside of the joint to be joined. The flow path may be narrowed or blocked due to resin dripping. In addition, foreign matter may enter the pipe for some reason. However, in such a case, air or water does not come out of the valve-equipped hose at the time of air release in the above-mentioned valve open state performed before the dynamic pressure test step, whereby a clogged portion exists in the main pipe or the branch pipe. Can be easily confirmed.

The above-mentioned dynamic pressure test is performed by alternately repeating the operation of pushing water into the main pipe and the branch pipe and the operation of withdrawing water to apply pressure fluctuations (impact), so that defective fusion defects or defective fusion defects are caused. The location leaks water due to the impact, so that a defective location can be easily confirmed. At this time, the operation of pushing water into the main pipe and the branch pipe and the operation of pulling out water are performed with a pressure difference of 10 kgf / cm ² or more and 10 to 3 times.
By performing the process 00 times, the incompletely fused portion can be almost completely detected.

After the dynamic pressure test, the valve is opened, the dynamic pressure tester is removed from the inlet end of the main pipe, an air hose is connected to the inlet end of the main pipe, and air is sent into the main pipe and the branch pipe. , Water can be drained quickly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for testing dynamic pressure of a prefabricated piping unit according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an example of a prefabricated piping unit, FIG. 2 is a plan view showing another example of a prefabricated piping unit,
FIG. 3 is a front view showing an example of a dynamic pressure test mode, and FIG. 4 is an explanatory diagram showing pressure values and dynamic pressure times of the dynamic pressure test.

The prefabricated piping units to which the present invention is applied include the prefabricated piping unit according to the branching method shown in FIG. 1 and the prefabricated piping unit according to the header method shown in FIG. The prefabricated piping unit according to the branching method shown in FIG. 1 is processed as a water supply pipe or a hot water supply pipe in a factory, for example, based on a piping diagram of a single dwelling unit of an apartment house.
In this processing, a plurality of branch pipes 2 made of the same flexible resin pipe are branched into a main pipe 1 made of a flexible resin pipe such as a polybutene pipe or a cross-linked polyethylene pipe via a joint 3 such as a Y-shaped or T-shaped pipe. Connected. The connection between the main pipe 1 and the branch pipe 2 is performed by heat fusion bonding or electric fusion bonding. In the electric fusion bonding, a joint in which a heating wire is embedded is used, and at the time of joining, the heating wire is energized to heat and fuse the joint and the main pipe 1 or the branch pipe 2 to join them. The prefabricated piping unit by the header method shown in FIG. 2 is based on a piping diagram at a factory, and a main pipe 1 made of a flexible resin pipe such as a polybutene pipe or a cross-linked polyethylene pipe is used as a water supply pipe or a hot water supply pipe. A plurality of branch pipes 2 are connected via one header 4 by heat fusion bonding or electric fusion bonding. At the inlet end 1a of the main pipe 1,
Generally, a connection fitting 10 such as a socket for connecting to a water heater or the like is provided. At the distal end of each branch pipe 2, a faucet mounting joint 11 for connection to a bathtub, a washing machine, a sink, a kitchen sink, or the like is provided.

The present invention is characterized by a method of performing a water leak inspection at a factory before shipping the prefabricated piping unit A pre-processed at the factory. Hereinafter, the procedure of this inspection will be described.

First, as shown in FIG. 3, the prefabricated piping unit A is wound in an annular shape having a diameter of about 1 to 2 m, several portions of which are bound by a band 5 or the like, and then suspended on a hook F or the like. Then, a dynamic pressure testing machine 6 is connected to the inlet end 1a of the main pipe 1, and a hose 8 with a valve 7 is connected to the distal end of each branch pipe 2. The dynamic pressure tester 6 includes a pump, a pressure gauge, and the like.

Next, after the valve 7 is opened, air is removed from each of the pipes 1 and 2 while water is supplied from the dynamic pressure tester 6 to the main pipe 1 and the branch pipe 2. At this time, if there is a clogged portion in the main pipe 1 or the branch pipe 2 due to a fusion defect, foreign matter mixing, or the like, air or water is supplied to the hose 8 with a valve.
, The presence or absence of the clogged portion can be easily confirmed. When the main pipe 1 and the branch pipe 2 are filled with water by this air release, the valve 7 is closed.

Next, a dynamic pressure test is performed in this state.
The dynamic pressure test operation of the dynamic pressure tester 6 by the operation of pulling the operation to push the water into the main pipe 1 and the branch pipe 2, preset low pressure value (0~5Kgf / cm ²⁾ and a high pressure value (main 1 and branches An operation of automatically reciprocating between a yield stress of the material of the tube 2 and 15 to 30 kgf / cm ² for a predetermined time is performed automatically (FIG. 4).
Or see FIG. 5). The reciprocating operation is repeated 10 to 300 times, more preferably about 100 times. When the pressure fluctuation is applied to the main pipe 1 and the branch pipe 2 in this way, a defective portion such as defective fusion can be detected more reliably and easily than when simply applying hydrostatic pressure.

After the dynamic pressure test, the valve 7 is opened, the dynamic pressure tester 6 is detached from the inlet end 1a of the main pipe 1, and the main pipe 1 is removed.
An air hose is connected to the inlet side end portion 1a of the, and air is sent into the main pipe 1 and the branch pipe 2 to drain water. Thereby, water can be quickly drained from the main pipe 1 and the branch pipe 2.

[0017]

According to the method for testing the dynamic pressure of a prefabricated piping unit of the present invention, it is possible to easily and surely detect a defective portion such as a fusion defect before shipping, and to obtain a prefabricated piping having high quality and excellent reliability. Advantageously, a unit can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a prefabricated piping unit.

FIG. 2 is a plan view showing another example of a prefabricated piping unit.

FIG. 3 is a front view showing an example of a dynamic pressure test mode.

FIG. 4 is an explanatory diagram showing a pressure value and the number of times of dynamic pressure in a dynamic pressure test.

FIG. 5 is an explanatory diagram showing pressure values and the number of dynamic pressures in a dynamic pressure test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main pipe 2 Branch pipe 3 Joint 4 Header 6 Dynamic pressure tester 7 Valve 8 Hose with valve

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Haruki Matsuura One of 153 Taji Yonemachi, Kishiwada-shi, Osaka F-term in Nippon Steel Pipe Fitting Co., Ltd. 2G067 AA16 BB04 CC02 DD05 EE08

Claims (3)

[Claims] 1. A dynamic pressure test method for a prefabricated piping unit in which a main pipe made of a flexible resin pipe and a branch pipe are previously fusion-bonded via a joint or a header at a factory, comprising: an inlet end of the main pipe; And connecting a hose with a valve to the distal end of each branch pipe, and then opening the valve, filling the main pipe and the branch pipe with water from the dynamic pressure tester, and filling each pipe. And a step of repeating the operation of pushing and pulling water from the dynamic pressure tester into the main pipe and the branch pipe many times alternately, and then closing the valve. Pressure test method for prefabricated piping unit. In 2. A pushing operation and withdrawal of water into the main pipe and the branch pipe operation and the pressure difference 10 Kgf / cm ² or more 10-300
The method according to claim 1, wherein the test is performed twice. 3. The method according to claim 1, wherein after the dynamic pressure test, the valve is opened, the dynamic pressure tester is removed from the inlet side end of the main pipe, and air is sent to the main pipe and the branch pipe to drain water. 3. A method for testing a dynamic pressure of a prefabricated piping unit according to 2.