JP5946061B2 - Flushing method for piping - Google Patents

Description

  The present invention relates to a pipe flushing method.

  When piping is newly installed or added to a building or when existing piping is repaired, foreign matter may enter the piping. Therefore, flushing is always performed as cleaning in the piping before the function inspection and the trial run in the installed or repaired piping. Of course, flushing is also performed to remove residues and the like attached to the piping by using the piping.

  The flushing of piping is to remove foreign matters in the piping (contaminants in the piping, residues adhering to the inside of the piping, etc.) due to the speed and impact of the fluid generated by flowing the fluid through the piping. By performing flushing to ensure cleanliness in the pipe, troubles such as damage to the pipe and malfunction of the pipe can be prevented, and clogging of the pipe and the filter can be prevented. Therefore, it becomes possible to normally operate devices connected to the pipe.

  As an object to be flushed, for example, there is a pipe of a nuclear power plant. In piping for the application of radioactive materials in nuclear power plants, flushing leads to a reduction in the environmental dose equivalent rate and a reduction in worker exposure.

  Generally, a large amount of water is used for flushing pipes, and it is also expensive to treat waste water that is water used for flushing pipes. Therefore, there is a need for a flushing method that has high cleaning efficiency and can be performed with a small amount of water.

JP-A-5-5799

  As a flushing method for piping in which the amount of water to be used is reduced, there is, for example, Patent Document 1. This is a flushing method using a mixed flow of water and air that continuously supplies air into a pipe and removes foreign matter in the pipe by intermittently supplying water.

  By using a mixed flow in which water and air are mixed, the flow rate of water can be increased. An increase in the water flow rate leads to an improvement in the efficiency of removing foreign substances in the pipe. Moreover, the residue adhering to the inside of the pipe among the foreign matters in the pipe is peeled off by friction with water. The increase in the flow rate of water increases the friction between the residue adhering to the inside of the pipe and the water, and also leads to an improvement in efficiency for peeling the residue adhering to the inside of the pipe.

  However, the amount of water used for flushing is still large. In addition, water may leak from the pipe being flushed due to poor connection or damage of the pipe. In this case, the supply of water is stopped, and the water already supplied into the pipe is discharged, and then the poorly connected part or damaged part of the pipe is repaired. Then, flushing is performed by supplying water into the pipe again. Thus, the water supplied into the defective pipe is wasted, and the amount of water used as a whole further increases. Of course, since the amount of wastewater increases, the cost for wastewater treatment also increases.

  The present invention has been made in view of the above problems, and an object of the present invention is to eliminate the risk of water leakage due to piping defects and to reduce the amount of water used for flushing.

  A flushing method for piping according to a first invention for solving the above-mentioned problem is a flushing method for piping that cleans the inside of a piping, and connects an air supply facility to one end side of the piping to be cleaned, and A discharge facility is connected to the other end of the pipe, and the supply valve provided in the air supply facility and the discharge valve provided in the discharge facility are closed, and then the supply valve is opened to release air from the air supply facility. Air formed by supplying the pipe with leakage inspection in the pipe, opening the discharge valve to discharge the air used in the leakage inspection, and supplying new air from the air supply facility to the pipe According to this flow, foreign matter in the pipe is discharged.

  In the pipe flushing method according to the second invention for solving the above-mentioned problem, the pipe is provided with one or more on-off valves to divide the inside of the pipe into a plurality of spaces, and the air supply equipment side following the supply valve. The leakage inspection is performed step by step by opening sequentially from the on-off valve.

  In the flushing method for piping according to the third invention for solving the above-mentioned problem, the water supply facility is connected to the one end side of the piping along with the air supply facility, and after the air used in the leakage inspection is discharged, The supply valve is closed, the water supply valve provided in the water supply facility is opened, water is supplied from the water supply facility to the pipe, and foreign matter in the pipe is further discharged by the flow of water flowing in the pipe. It is characterized by that.

  In the flushing method for piping according to the fourth invention for solving the above-described problem, the other end side of the piping is disconnected from the discharge facility, and the other end side of the piping is subject to cleaning different from the piping. And connecting one end side of the pipe to the other end side of the other pipe by performing a leak test on the other pipe, and Foreign matter in the another pipe is discharged.

  According to the flushing method for piping according to the first invention, by supplying air to the piping and performing a leakage inspection in the piping, when using the piping or flushing the piping with water, Will not leak. In addition, because the air supplied to the pipe is used for leak inspection and the pipe is flushed with air, foreign matter in the pipe can be removed without using water, improving the cleanliness of the pipe. Can be made.

  According to the flushing method for piping according to the second aspect of the present invention, when an on-off valve is provided in the piping and the inside of the piping is divided into a plurality of spaces, when leakage inspection is performed by air and leakage is confirmed, the leakage location of the piping Since the search range is small, the time required to find the leaked portion can be shortened.

  According to the flushing method for piping according to the third invention, the cleanliness in the piping is improved by performing flushing with air using the air used in the leak inspection. By performing the flushing by the above, the cleanliness in the pipe can be further improved. Of course, since the leak inspection with air is performed before the flushing with water, the water does not leak from the pipe during the flushing with water. Further, since the cleanliness in the pipe is improved by flushing with air, the amount of water used for improving the inside of the pipe to a predetermined cleanliness is reduced by flushing with water.

  According to the flushing method for piping according to the fourth aspect of the present invention, leakage inspection and flushing can be performed in another piping without re-installing the air supply facility, the water supply facility, and the discharge facility. Installation work of supply equipment and discharge equipment can be reduced.

It is explanatory drawing which shows the whole structure of piping etc. in the flushing method of piping which concerns on Example 1. FIG. It is explanatory drawing which shows the example of a change of piping in the flushing method of piping which concerns on Example 1. FIG.

  Embodiments of a flushing method for piping according to the present invention will be described below in detail with reference to the accompanying drawings. Needless to say, the present invention is not limited to the following examples, and various modifications can be made without departing from the spirit of the present invention.

  With reference to FIG. 1, a description will be given of the configuration of piping equipment to be flushed and temporary equipment for performing flushing in the present embodiment.

  As shown in FIG. 1, a temporary supply facility 2 that supplies air and water and a temporary discharge facility 3 that discharges air and water are connected to the piping facility 1 as a temporary facility.

  The piping facility 1 includes a first pipe 10, a second pipe 11, and a third pipe 12 from the upstream side (right side in the drawing). The first pipe 10 is connected to the second pipe 11 via the first connecting part 20, and the second pipe 11 is connected to the third pipe 12 via the second connecting part 21. The second pipe 11 is provided with an on-off valve 30 that adjusts the flow rate of air, water, or the like.

  In this embodiment, in order to measure the pressure in the pipe, the first pressure gauge 40 is installed in the first pipe 10 and the second pressure gauge 41 is installed in the third pipe 12.

  The temporary supply facility 2 includes an air supply line 50 for supplying air and a water supply line 60 for supplying water.

  The air supply line 50 includes an air tank 51 that stores compressed air compressed by a compressor (not shown), a filter 52 that removes foreign matters contained in the air to be vented, and an air supply valve 53 that adjusts the flow rate of air. The air tank 51 is connected to the first pipe 10 through the filter 52 and the air supply valve 53.

  The water supply line 60 includes a water tank 61 that stores water used for flushing, a water supply pump 62 that pumps water from the water tank 61, a first water supply valve 63 that adjusts the flow rate of water, and a second water supply. The valve 64 is connected to the first pipe 10 together with the air supply line 50 from the water tank 61 through the water supply pump 62, the first water supply valve 63 and the second water supply valve 64.

  The temporary discharge facility 3 includes a discharge valve 70 for adjusting a flow rate for discharging air or water used for flushing, a discharge port 71 for discharging air or water used for flushing, and a waste water tank for storing discharged water. 72, is connected to the discharge port 71 from the third pipe 12 through the discharge valve 70, and a waste water tank 72 is installed below the discharge port 71.

  Next, the procedure for flushing the inside of the piping will be described with reference to FIG.

  First, all the valves (the air supply valve 53, the first water supply valve 63, the second water supply valve 64, the on-off valve 30, the discharge valve 70) in the piping facility 1, the temporary supply facility 2, and the temporary exhaust facility 3 are turned on. It shall be in a closed state (a sealed state in which the inside of adjacently connected pipes cannot be ventilated and passed water).

  Next, the air supply valve 53 is opened. The compressed air in the air tank 51 passes through the filter 52 and is supplied upstream of the on-off valves 30 of the first pipe 10 and the second pipe 11. It is confirmed that the pressure measured by the first pressure gauge 40 installed in the first pipe 10 is a predetermined pressure. If the first pressure gauge 40 indicates a predetermined pressure, it can be confirmed that there is no air leakage upstream of the on-off valve 30 of the first pipe 10 and the second pipe 11.

  If the pressure measured by the first pressure gauge 40 does not reach a predetermined pressure, it is determined that there is air leakage upstream of the on-off valve 30 of the first pipe 10 and the second pipe 11. Can do. And the leak location in the upstream from the on-off valve 30 of the 1st piping 10 and the 2nd piping 11 used as the object of a leakage inspection is found. For example, when soap water is applied to the outer surface of a pipe or a connecting part, bubbles of soapy water (soap bubbles) are formed by the air leaking from the leaked portion, so that the leaked portion can be found. Close the air supply valve 53 and repair the leaked part. When the repair is complete, perform the above leakage inspection again.

  Until it can be confirmed that there is no air leakage on the upstream side of the on-off valve 30 of the first pipe 10 and the second pipe 11, the work of leak inspection and the repair of the leaked portion are repeated.

  Next, the on-off valve 30 is opened. The compressed air in the air tank 51 is supplied to the downstream side of the on-off valve 30 of the second pipe 11 and to the upstream side of the third pipe 12 and the discharge valve 70 of the temporary discharge facility 3. It is confirmed that the pressure measured by the second pressure gauge 41 installed in the third pipe 12 is a predetermined pressure. If the second pressure gauge 41 indicates a predetermined pressure, it can be confirmed that there is no air leakage downstream of the on-off valve 30 of the second pipe 11 and the third pipe 12.

  When the pressure measured by the second pressure gauge 41 does not reach a predetermined pressure, it is determined that there is air leakage downstream of the on-off valve 30 of the second pipe 11 and the third pipe 12. Can do. Find the leak location, close the on-off valve 30 and repair the leak location. When the repair is complete, perform the above leakage inspection again.

  Until it can be confirmed that there is no air leakage in the downstream side of the on-off valve 30 of the second pipe 11 and the third pipe 12, the operation of leak inspection and the repair of the leaked portion are repeated.

  With the above operation, the work of the leakage inspection and the repair of the leakage portion in the first pipe 10, the second pipe 11, and the third pipe 12 are completed.

  The predetermined pressure is not limited as a numerical value, but is preferably set to a pressure applied to the pipe in the subsequent flushing with water or a pressure equivalent to the pressure applied to the pipe in the intended use. By performing a leak test at such a sufficiently high pressure, the reliability regarding the presence or absence of a leak is improved.

  Next, the discharge valve 70 is opened. The air used in the leak inspection in the first pipe 10, the second pipe 11, and the third pipe 12 is discharged from the discharge port 71, and new compressed air in the air tank 51 is supplied to the first pipe 10 and the second pipe 10. To the first pipe 11 and the third pipe 12. An air flow from the air tank 51 to the discharge port 71 through the first pipe 10, the second pipe 11, and the third pipe 12 is formed. Due to this air flow, foreign matters in the first pipe 10, the second pipe 11, and the third pipe 12 (contaminants in the pipe, residues adhering to the inside of the pipe, etc.) are discharged from the discharge port 71. Is done. The air supply valve 53 is closed.

  By the above operation, flushing by air in the first pipe 10, the second pipe 11, and the third pipe 12 is completed, and the first pipe 10, the second pipe 11, and the third pipe 12 are cleaned. The degree improves.

  Subsequently, the water supply pump 62 of the water supply line 60 is activated, the first water supply valve 63 is opened, and the second water supply valve 64 is opened. Water in the water tank 61 is supplied to the first pipe 10, the second pipe 11, and the third pipe 12 by the water supply pump 62, and is discharged from the discharge port 71 in the temporary discharge facility 3. The water discharged from the discharge port 71 is stored in the waste water tank 72 as waste water. The second water supply valve 64 is closed, the first water supply valve 63 is closed, and the water supply pump 62 is stopped.

  By the above operation, flushing with water in the first pipe 10, the second pipe 11, and the third pipe 12 is completed, and the first pipe 10, the second pipe 11, and the third pipe 12 are cleaned. The degree is improved.

  The cleanliness inside the first pipe 10, the second pipe 11, and the third pipe 12 is improved by flushing with air. That is, in the case where the cleanliness in the first pipe 10, the second pipe 11, and the third pipe 12 is improved to a higher cleanliness, the first pipe 10 and the second pipe 2 when flushing with water are performed. The inside of the pipe 11 and the third pipe 12 has a higher cleanliness than before. Therefore, the amount of water used for flushing with water can be reduced.

  When high cleanliness is not required as in this embodiment, flushing with water using the air supply line 50 may be performed instead of flushing with water using the water supply line 60. Of course, the amount of water to be used can be further reduced by performing flushing with a mixed flow of water and air after the air leakage inspection and flushing.

  Further, the temporary supply facility 2 and the temporary discharge facility 3 which are temporary facilities of the present embodiment can be diverted to perform flushing of other pipes. For example, as shown in FIG. 2, by connecting the piping facility 1 and another piping facility 4 with a temporary piping 80, the temporary supply facility 2 and the temporary discharging facility 3 can be connected to another piping facility 4 without re-installation. Leakage inspection and flushing can be performed. Since leak inspection and flushing in another piping facility 4 can be performed in the same manner as the piping facility 1 described above, description thereof is omitted.

DESCRIPTION OF SYMBOLS 1 Piping equipment 2 Temporary supply equipment 3 Temporary discharge equipment 10 1st piping 11 2nd piping 12 3rd piping 20 1st connection part 21 2nd connection part 30 On-off valve 40 1st pressure gauge 41 2nd Pressure gauge 50 Air supply line 51 Air tank 52 Filter 53 Air supply valve 60 Water supply line 61 Water tank 62 Water supply pump 63 First water supply valve 64 Second water supply valve 70 Discharge valve 71 Discharge port 72 Wastewater tank

Claims (4)

A flushing method for piping that cleans the inside of the piping,
While connecting the air supply equipment to one end side of the pipe to be cleaned, connecting the discharge equipment to the other end side of the pipe,
From a state in which the supply valve provided in the air supply facility and the discharge valve provided in the discharge facility are closed, the supply valve is opened and air is supplied from the air supply facility to the pipe to perform a leak inspection in the pipe. ,
Opening the discharge valve to discharge the air used in the leakage inspection and discharging foreign matter in the pipe by the flow of air formed by supplying new air from the air supply facility to the pipe. Flushing method for piping characterized by   The pipe is provided with one or more on-off valves, the inside of the pipe is divided into a plurality of spaces, and the leak check is performed in stages by sequentially opening the on-off valve on the air supply facility side after the supply valve. The flushing method of piping according to claim 1 characterized by things. A water supply facility is connected to the one end side of the pipe along with the air supply facility,
Close the supply valve after exhausting the air used in the leak test,
The water supply valve provided in the water supply facility is opened to supply water from the water supply facility to the pipe, and the foreign matter in the pipe is further discharged by the flow of water flowing in the pipe. The flushing method for piping according to claim 1 or 2. Disconnect the other end of the pipe and the discharge facility,
By connecting one end side of the pipe to be cleaned separately from the pipe to the other end side of the pipe by a temporary pipe, and by connecting the discharge facility to the other end side of the other pipe,
The pipe according to any one of claims 1 to 3, wherein a leak inspection is performed in the other pipe and foreign matter in the other pipe is discharged in the same manner as the pipe. Flushing method.

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