JPS608393B2 - Piping construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing piping in the construction of, for example, a nuclear power plant.

First, we will discuss the piping construction method used in conventional nuclear plant construction.

In the construction of equipment and piping in nuclear plant construction, the equipment is used as the starting point for piping construction, and as soon as the hemming area is secured, the equipment is brought in and the hemming is carried out. . For example, an emergency pump installed on the lowest basement floor of a nuclear power plant has a total length of about 1 cm, as shown in Figure 1.
Although it is a large, rigid pump that reaches 1 skin, once the hemming area and the base 1 are completed, the top surface of the base is leveled and the sole plate 2 is set.

Pump 3, which has completed factory testing, will be disassembled and transported to the site. At the site, first, the invera and casing 4 are hemmed, and then the pump body 5 with the suction/zzle and discharge nozzle that will be connected to the piping is installed, and centering is performed with high precision. Next, the piping b is hemmed using the suction nozzle and discharge nozzle of the pump body as reference points. Generally, the pump 3 and piping b are bolted together so that they can be disassembled and transported, and by tightening these bolts, the installation of the pump 3 and piping b is completed. Next, pipes 7 are successively added to the installed pipes and welded. Once welding of the piping is completed, we will prepare the piping for a water pressure test and cleaning the piping. Even if cleaning water is poured into the pump, water cannot be circulated because it is a vertical pump, and the pump cannot hold up to the water pressure test pressure, so it is necessary to bypass the pump, so piping b is
The part that connects to the pump nozzle has flanges on both ends, so remove them and make the pump body independent. On the piping side,
Temporary piping 8 as shown in FIG. 2 is manufactured, connected to piping 7, and both are bolted together. In this way, perform the water pressure test and pipe cleaning, and once completed, remove the pipe 8,
Restore piping b and fix pump 3. After this pump 3
A motor 9 is mounted on the motor 9, and the pump's invera is connected and fixed. After placing the conduit on the motor terminal block and running the cable, electrical tests are conducted with the power supply panel and control panel, and work begins on pump operation. The conventional piping construction method is as described above, but this method has the following serious drawbacks.

First, when starting piping, it is necessary to install the equipment in advance at the earliest possible time when it is possible to enter the building.

As a result, from the installation of the equipment to the test run,
The plant has been stuck in poor local environmental conditions for about two months, and as regular operations cannot be carried out during this period, the situation is not favorable for quality control. In particular, in the case of the vertical pump explained in the previous example, since it is installed in a basement and in bedrock with a bit installed at the bottom, the pump's casing and other parts may rust due to humidity and water accumulation. may occur or deform,
Disassembly and inspection are required before test operation begins again. In addition, only the pump body 5 shown in Figure 1 is directly required to construct the piping, but since it is actually difficult to ship only this part from the factory, the pump as a whole must undergo advanced quality control from an early stage. The products are manufactured based on the original specifications and shipped after undergoing factory performance tests. Parts such as mowers that are not required for piping construction locally must be stored at the factory or on-site warehouse for several months, which requires a great deal of cost and labor to maintain performance and ensure quality control. thing. Furthermore, since expensive equipment must be manufactured from an early stage, material and manufacturing costs and investments occur quite early in the plant construction process, which is not a favorable situation for business management. Additionally, during water pressure tests and cleaning of piping, since water cannot flow through the pump body, it is necessary to temporarily isolate the pump body from the piping, requiring temporary piping for this purpose and requiring additional man-hours.

These several factors are contributing factors to the lengthening of the plant construction period. It is an object of the present invention to provide a piping construction method that eliminates these drawbacks, improves quality, improves work efficiency, significantly reduces costs, and significantly shortens construction period.

The feature of the present invention is that ``a high-precision model that simulates the equipment is manufactured without directly using the equipment that serves as a standard for piping construction, and this is carried to the site before piping construction.
Water Pressure Test: After cleaning the pipes, the model is removed and the original equipment is then installed to construct the plant. An embodiment of the present invention will be described below with reference to the drawings.

Figures 3a and 3b are diagrams showing highly precisely made models of pumps and the like that serve as piping standards. This model is not a model of the equipment itself; rather, it is manufactured with the exact position and size of flanges, etc. of piping connections, and the installation positions of hem bolts, etc. (instead of copying the external shape as is). It's fine if you have it.

In other words, the two connecting parts 16 that have the structure and function of the piping connecting parts of the device are connected to the piping 1 that can withstand water pressure tests and cleaning.
7, the two connecting surfaces are welded while maintaining the distance between the surfaces with high accuracy, and this is fixed on a table 18 made of steel with accurate horizontal and horizontal dimensions of the connecting portion. Next, prior to piping construction, this model 10 is accurately installed on the foundation 11 set for the equipment in question, and the piping 12 is constructed as a reference point for piping construction.

After the piping is completed, the water pressure test and cleaning of the piping is performed by directly passing water through the model 10 using this model. Then, after completing the water pressure test and cleaning, select an appropriate time to remove the model 10 and hem the device. At this time, as stated at the beginning, since the model structure has sufficient precision for the piping connections of the equipment, it is clear that there will be no problems in attaching the equipment and fitting the connections. As explained above, by implementing the present invention, "storage of the equipment seen in the above-mentioned large pump installation example, arrangement of storage space, quality control and maintenance during the storage period" that occur in connection with this storage. In addition to solving these problems, it also eliminates the need for temporary piping to bypass equipment during piping water pressure testing and piping cleaning.

In addition, when it comes to bringing in equipment, the most appropriate time required can be selected within the overall process, and at the same time, the period between equipment testing at the factory and equipment testing at the site is shortened, ensuring equipment performance. It is also advantageous in

Additionally, there is no need to install or remove temporary piping, reducing man-hours. There is no need to manufacture expensive equipment at an early stage, and costs are also favorable from an economic point of view.

It is easy to understand that the combination of these various effects will significantly shorten the plant construction period and reduce costs.

Although the present invention has been described above with reference to specific examples thereof, the present invention is
It goes without saying that the present invention is not limited to these specific embodiments, and that many changes and modifications can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the final piping construction state, Figure 2 is the
Figure 3A and b are side and front views showing an embodiment of the model used in the piping construction method of the present invention; Fig. 4 is an explanatory diagram showing an example of piping construction using a model according to the present invention. 10...Model, 12...Piping. Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] 1. When constructing piping, a model that accurately simulates the connection structure of the equipment connected to the piping and has through-holes strong enough to withstand the specified test pressure is installed at the equipment installation location, and then the specified piping construction is carried out. A piping construction method in which, after carrying out a water pressure test and cleaning, the model is removed and the equipment is installed in its place to complete the construction.