JPS5879133A - Water pressure testing method - Google Patents

Abstract

PURPOSE:To judge the pass or fail accurately based on an objective reference, by comparing the pressure value after the water pressure to be tested is maintained for a specified period with an allowable pressure value, in consideration of the pressure reduction due to remaining air quantity, when the pressure is applied in order to attain the water pressure to be tested. CONSTITUTION:The water pressure test of a water pipe in which mortar lining is applied is performed as follows. First of all, air is evacuated and water is injected. Thereafter, the pressure is preliminarily applied in a process (c). This pressure is maintained for 24hr. The pressure is further applied in order to attain the pressure to be tested in a process (e). A pressure value Ph after 24hr is measured, and the value is compared with the allowable pressure value Pk. If Ph>=Pk, the pressure passes the test. If Ph<Pk, the pressure fails in the test. In order to compute the allowable pressure value Pk, at first the quantity of theoretical additional water for pressurization up to the pressure to be tested P is obtained from the pressure value Ph. Said additional water quantity is required because of the absorption of water by the lining, dissolution of remaining air into water and the like. The Pk is obtained by a specified expression from said water quantity and the remaining air quantity. Therefore the pass or fail can be accurately judged based on the objective reference.

Description

[Detailed description of the invention] The present invention relates to a hydraulic testing method.

For example, when conducting a hydraulic pressure test on a large-volume test object such as a buried water pipe, conventionally the test object was filled with water and then
After the test, pressurize until the water hits, and exceed 1' in a constant j()1 period.
Pass/fail judgment was made based on the degree of pressure drop in 4>. However, in such a trial inspection method, a pressure drop may occur not only due to the initial pressure drop due to slight movement of the tube handle or pipe, but also due to the dissolution of water and residual V gas in the lining. ), Even if the test is pre-pressurized for a certain period of time, the pressure of the test (((') is unavoidable and there is no standard, so it gives anxiety to the user and it is dangerous for amateurs to judge pass/fail. Met.

There is also a method of replenishing water to maintain the test water pressure even after pressurizing it to the test water pressure, and making a pass/fail judgment based on this replenishment water. However, in this case as well, there is a problem in determining the allowable range of makeup water M, as described above.

In addition, the pressure drop due to water absorption to the lining and the slight shift of the irregularly shaped pipe IJ1 where uneven force acts, or the additional water 4.1s
can be calculated using a certain coefficient from the lining area and the number of irregularly shaped pipes, but since the pressure drop due to the dissolution of residual air or make-up water cannot be known in advance, the residual air t cannot be known in advance. It was not possible to determine the range objectively.

The present invention has been developed in view of these problems, and has been developed to reduce the pressure drop from the water pressure in the test and to allow additional water to be added to the water pressure in the test. ! +4 to the customer'gJ,l, and perform the pass/fail test 11 before measurement. ■Prepressurize for a certain period of time at a water pressure slightly lower than the test water pressure, and at the beginning of the test tU-+ JJ
In addition to causing 4 heat changes in advance due to the
After that, pressurize to the test water pressure and measure the make-up water from this pre-pressurization until the test water pressure is reached. 0) Calculate the amount of residual air from the make-up water amount and calculate the residual air in J and S during the test period. 1 royal power (!jg lower or Hl (
Calculate the amount of additional water required to reach the test water pressure, and calculate this as t+li
The pass/fail judgment of the measured value is made based on +l-L/ta1;'1 volume rllii.

Next, embodiments of the present invention will be described based on the drawings. 1st
The figure shows mortar lining of less than 2 hl]1. Tamizudori 11''! Water pressure test by pressure management against road
) shows the tire gram. In the embodiment shown in FIG. 1, the exhaust state is set to 7i+? in step (a). i) Gradually fill water with the magazine 1, then open the air valve in step (+)), remove air little by little, and then open the air valve in step (c). IJ7], then pre-pressurize by supplying water until the water pressure becomes a water pressure (p-Jp) slightly lower than the test water pressure ip). Next, this pre-pressurized state is maintained in a closed state for a certain period of time (for example, 24 hours). With this pre-pressure holding process 11(d), pipe) 1 wood handle and pipe copy transfer! I! Ij
This change in internal volume occurs at the early stage of the folding process, and phenomena such as water absorption by the lining, dissolution of residual air into water, and micro-movement of irregularly shaped pipes subjected to uneven forces are stabilized.

After the specified period of time has elapsed, water is supplied and the water pressure reaches (p-Jp).
), further spinning, and in step (e) pressurize until the test water pressure (p) is reached, and the water pressure becomes (p).
- Measure the amount of make-up water (Qi) from (Jp) to (p).

Next, a water pressure test step (f) is entered in which the test water pressure (p) is maintained in a closed state for a certain period of time (for example, 24 hours), and the pressure value (pl+) is measured after the certain period of time has elapsed. Then, when the measurement is finished, the drainage works) ffi! (g)
Then υ1: water is poured from inside the pipe and the test is completed.

The above actually measured pressure value (ph')o) pass/fail judgment is made by comparing it with the allowable pressure value (pk) obtained as follows [11
11≧pk, pass, pb (pk, fail.

In calculating the allowable pressure value (pk), first calculate the theoretical additional mercury, which is assumed to be 8 columns for pressurizing from the measured pressure value (ph) to the test pressure value. Factors that require additional water include an additional amount of water Qc due to water absorption by the lining, additional water MQa due to dissolution of residual air into water, and additional water ff1Qb due to slight movement of the irregularly shaped pipe to which uneven force is applied. Qc can be calculated by multiplying the lining surface i per unit length (kgAn) and the phase of the pipe length Q by a coefficient obtained experimentally, and can be given as in the following equation (1).

Qc=0.0007-G-L-...(1)
Q11 Residual air amount in the pipe Va (a and test water 1:1'-p
(kQ/cd), and the residual air amount Va is given by the following equation (2) obtained experimentally from = 4.8
4 X 1O-5) and the internal tg product w (1, which is given by formula (3) by ffi.

Qa--4158゛V bill　　　　　　316161. .

, (2゜p −1−1 va== (Qi2・W・ΔI))(p−IJ+IX
p+1) ,,0. , (3゜Jp) Here, equation (3) calculates the amount of water in the pipe when the residual air amount in the pipe is Va, the amount of water in the pipe when the pressure a is p, and the amount of water in the pipe when the pressure a is p. 2-(w,)JP-1
-1) (i 10 β (p-29) It is obtained by finding Va from a formula in which the difference Ql-02 from September is equal to the replenishment water amount Qi.

Qb is given by equation (4), which is experimentally obtained from the number N of irregularly shaped pipe sections to which the unbalanced force is applied and the outer diameter of the pipe.

Ql) = 0.157・N-D2 ・・・・・・
...(4) Thus, the theoretical value of the additional water amount is Qm =Qc+Qa+Qb ---=
(5), and the allowable additional water amount Qk is the correction coefficient f
Multiplying by (-1, 2), it is given by Qk = f-Qm --(Q). Then, the allowable pressure pki; j b This allowable additional water amount Qk, the residual air 1ii;
) formula is the allowable additional water fH'j, Ql from the state at the start of the test.
The pressure when [ is removed from t′i・ is the allowable pressure F1
(deihtosu/)by Va-1AQk
As an adult, pkp+1 can be obtained from this by calculating pk+1.

”Total 1) °V a r ・・・・・・・・・
(7)p"""(p-t-1)Qk10Va In this way, r1 customer F'3 (IH'r (p
Judgment is made on whether the measured pressure value (1) (11) passes or fails as described in 2. If it passes, the test is completed, and if it fails, the air valve, θ1 discharge valve, and 1ilij end cover are Investigate and confirm leaks from valves, etc. and abnormalities in pipelines, and take appropriate action.
, After doing l, exit i1 exam l! ′! Do iJ.

The embodiment shown in Fig. 1 is a water pressure test using pressure control, but the water LIE f! Even with 1'Q, you can get M11 on the same pine tree. For example, as shown in Figure 2,
In the same process as shown in Fig. 1, the water pressure test step (f) is carried out, and the water supply is pressurized at a constant level, and the additional water JJ' required at that time is
k (Qh) is 1111 in total. And this fruit 11t
Compare lJ additional water volume (Qll) and allowable additional water volume (Qk) given by equation (6) above, and pass if Qh≦Qk.
Qll > Qk does not match.'? Let it be S.

Further, as shown in Fig. 3, the prepressure holding step (d) is entered in the same process as Fig. 1, and the water pressure is maintained at (p-Δp) for a certain period of time in this prepressure holding step (d). If the water pressure decreases, water is immediately replenished, and after a certain period of time, the pressure is increased in the pressurization step (e) until the test water pressure φ) is reached, and the replenishment water u (Qi) is measured. Water pressure test step (f) in which the pressurized state of this test water pressure (0) is maintained for a certain period of time.
When the water pressure drops, Cζ water is immediately added to maintain the water pressure at the test water pressure (p)t, and the amount of additional water (Qh) required to maintain the pressure is measured. This actual measurement addition 1t (Qh) and J' (-additional Mercury (Qk)
It can also be implemented as a test-taking method in which it is determined that Q11≦Qk passes, and Qll>Qk fails.

In this case, accurate judgment is made by employing equation (8) of one order instead of equation (5) as the theoretical addition M Qn.

Qm = Qc+Qa-1-Qb+Qt
−−= (+1) Here, Qt is the hydraulic test process (f
) is the amount of additional water based on the thermal expansion and contraction of water and residual air due to the difference in water temperature before and after the water pressure test, and is the amount of water before and after the water pressure test.
It is given by the following equation (9) from the difference ΔT ('C) and the intraluminal volume W (.

Qt −± (1,2X 10−' w +8.4
X10-' Engineering) Δ'1゛°°° (9) 1) 11 Although the above implementation ('l) described the hydraulic test j! of a water pipe lined with mortar, the present invention is applicable to other It is clear that it can also be used, for example, for pipelines without lining or irregularly shaped pipes. The invention is based on the water pressure test of each extraction plant, etc.
The calculation can be performed by appropriately selecting the ``additional AfflQ term in the equation (5)'' and adding the J negative value for the necessary factors ().

According to the water pressure test method of the present invention, as is clear from the above explanation, prepressurization is performed at a water pressure slightly lower than the test water pressure, and the required h [1
Calculate the amount of residual air (LL) from the amount of water supplied, and compare the actual pressure value or allowable additional water amount, which compensates for the pressure drop due to the dissolution of the residual air or additional water amount, with the actual value (this is how you judge pass/fail, so it is an objective method. Accurate judgment 11jr based on the standard becomes possible.

[Brief explanation of drawings]

1 to 8 are diagrams of embodiments of the method of the present invention. (a)... Water filling process, (b)... Air venting process, (
c)...Pre-pressure step, (d)...Pre-pressure holding step,
(e)...Pressure process + d, (f)...Hydraulic pressure test process,
(Ki)...Yoshihiro Morimoto, wastewater engineering agent

Claims (1)

[Claims] 1. Tested! After filling with water on the same day, test 1 (water resistance 1)
Prepressurize to a slightly lower water pressure, maintain this prepressurized state for a certain period of time in closed state #jF or pressure maintenance state f, then pressurize to the test water pressure, and continue from the prepressurization described in nII until reaching the test water pressure. If the make-up water t is measured and this pressurized state is closed for a certain period of time or maintained in a pressure maintenance state 1)' (J-C), after this fixed period of 1 period has elapsed, the amount of pressure drop during that period or 011 Pressurization or test water pressure up to the above test water pressure pl: Measure the additional water volume per 1 pipe, and calculate the pressure drop or additional water volume due to the dissolution of residual air calculated from the replenishment water drop by W [taking into account the water pressure or allowable additional water 14
A water pressure test method, characterized in that pass/fail is determined based on the measured value and the measured value.