JPS6298083A - Supporter for piping - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a small diameter piping support for nuclear power generation equipment,
In particular, the present invention relates to a support suitable for piping that has a high-temperature internal fluid and is subject to vibration.

[Background of the invention]

The support currently used in nuclear power generation equipment is the one disclosed in Japanese Patent Application Laid-Open No. 58-24681.

As described in the attached description, the support has an L-shaped base part and a raised part, a rib part is formed protrudingly at the boundary between the two parts, and a piping support part is formed on the upper part of the raised part.

The structure is such that the board is fixed together with the piping using U-shaped bolts.

However, it is necessary to ensure a gap (clearance) for thermal expansion in the circumferential direction of the piping, and no consideration has been given to piping that is subject to vibration.

Furthermore, as this type of support tool and support device, the
No. 9-127982 "U bolt for piping support", Utility Model No. 5
No. 9-121577 "Piping support structure" and Utility Model Application No. 1983-
No. 183574 "Clamp fittings J, etc." Also, the U bolt support device is disclosed in Utility Model Application Publication No. 59-197282 "U Bolt for Piping Support" for providing a gap to absorb the thermal expansion in the circumferential direction of the piping. A barb-shaped stopper is welded to a conventional U-bolt. It requires welding of small items such as stoppers, and is unsuitable when there is vibration.

Utility Model Application Publication No. 59-121577 ``Piping Support Structure'' has a structure in which a V block is welded to the side of a piping support member to support the piping, and there is a positional shift between the piping support position and the U bolt restraint position.

Utility Model Application Publication No. 59-183574 "Clamp fitting" has a structure in which two receiving members are attached by two bent bolts and expands or contracts on the supporting surface.

[Purpose of the invention]

An object of the present invention is to provide a support that allows free thermal expansion of piping in the circumferential direction and eliminates the need for conventional gaps for thermal expansion.

[Summary of the invention]

With conventional supports and support devices, a lot of man-hours are spent on securing gaps during construction in order to absorb the thermal expansion of piping in the circumferential direction, and this gap is also regulated by the "U bolt gap adjustment amount". If a post-construction inspection fails to meet the regulations, it must be re-constructed, subject to strict controls unique to nuclear power generation facilities.

Furthermore, in a small-diameter pipe that branches from a large-diameter pipe, vibrations due to the flow of internal fluid in the large-diameter pipe are likely to occur, and vibrations are particularly likely to occur near the branching point from the large-diameter pipe.

Due to this factor, there have been several dozen cases in the past where cracks occurred at the welded toe of the branch socket socket, leading to plant shutdowns. Therefore, if there is vibration in small-diameter piping, U
A common countermeasure is to restrain small-diameter piping with bolt support devices to prevent vibration. (Of course, if the vibration of the large-diameter piping is large, support and restrain the large-diameter piping.) However, in high-temperature piping, it is necessary to tighten the U bolts and take measures without securing the circumferential gap. This increases thermal expansion stress, and it is necessary to carefully consider the balance with vibration stress.

In order to solve one or more problems, the present invention is a support that allows free thermal expansion in the circumferential direction of piping and eliminates the need to maintain a gap for thermal expansion.

The present invention provides a support for a U-shaped bolt type support device that is often used for small-diameter piping, and is made of an elastic body that can bend in response to the circumferential thermal expansion of the small-diameter piping, thereby alleviating the thermal stress of the piping. This is a support for small-diameter piping, which is characterized by being able to prevent vibration, and the support has a deformable U-shaped structure, and the U-shape is formed in a direction perpendicular to the axis of the piping. This is a piping support tool characterized by:

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, IA is a support according to the present invention, 3 is a U-bolt, 4 is a nut, 5 is a pipe, and 6 is a base material.

The present invention has the above-described configuration, with 5 pipes installed on the support surface of the IA pipe support installed on 6 base materials, and fixed with 3U bolts and 4 nuts.

The IA piping support of the present invention has a U-shaped structure and is an elastic body capable of absorbing circumferential elongation of the piping. Therefore,
When constructing the support device, there is no need to pay particular attention to the gap between the 5 pipes and the 3 bolts, and the above-mentioned gap adjustment is not required.

Further, the IA support can be integrally formed by press working, which allows mass production compared to molding by casting, simplifies the manufacturing process, and improves productivity.

Note that the U-shaped structure of the support of the present invention may be the IB structure in FIG. 2 if the supporting load is large.

Since this configuration eliminates the need for a gap, it is possible to prevent piping vibration within the gap.

This made it possible to prevent the plant from shutting down due to vibration expansion due to U-bolt wear and damage caused by piping fatigue, which occurred recently in the existing plant.

Even in the event of an accident caused by cracks in the pipes, the structure can prevent vibrations, so it can be a highly reliable nuclear power generation facility.

Also, installing a U-shaped support at right angles to the piping axis is disclosed in Japanese Patent Application Laid-open No. 5
Compared to No. 8-24681, the overturning moment against the support due to friction between the support and the pipe due to thermal expansion in the axial direction of the pipe is reduced.

This eliminates the need for the upper nut required in the above-mentioned patent application.

〔Effect of the invention〕

According to the present invention, construction can be performed without providing a gap regarding the circumferential thermal expansion of small-diameter piping, and since there is no gap, it is also optimal for vibration prevention, and has the following effects.

(1) By eliminating the gap between the pipe and the support, pipe vibration is prevented and reliability is improved.

This can also be used to prevent past incidents of plant shutdowns due to leakage at the weld toe of small-diameter pipe branch seats due to pipe vibration, making it possible to supply highly reliable small-diameter piping systems.

(2) A support that allows thermal expansion of the piping in the circumferential direction and does not particularly restrict thermal expansion in the axial direction.

(3) Since the support is perpendicular to the piping axis, the support will cause friction against the axial thermal expansion of the piping.

Axial thermal expansion is smooth and difficult to cause.

(4) Since gap management is not required and construction is easy, it is possible to significantly reduce the number of travel stations.

(In the past, the main method of work was to insert a tin plate between the piping and the U port, tighten it, and then remove the tin plate to ensure a gap, but if too much # is attached, the tin plate (5) The upper nut for restraining the support of the conventional structure is no longer needed, and when installing the U bolt, the U bolt does not enter the piping in the same diagram, so remove the upper nut. After passing the U-bolt through the pipe, there is no need to bring the upper nut to the top of the U-bolt, which greatly reduces the number of man-hours.

(6) It is a support that can be integrally molded by press working, and can be mass-produced, and the manufacturing process is simplified, resulting in a significant improvement in productivity.

(7) Since the support is a U-shaped elastic structure, the piping vibration damping effect during short-term vibrations caused by earthquakes, shock waves, etc. is significantly increased compared to the conventional gap structure.

(8) Since the support device is simple and has few components, anyone can install it, reducing installation costs and man-hours, as well as eliminating the need for inspections to check whether the installation is within the allowable production limit or not. Become.

(9) There can be no need to redo or go back to areas outside the gap limit range.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing an embodiment of the present invention.
It is a perspective view in case the U-shaped structure of a support is double. DESCRIPTION OF SYMBOLS 1... Support tool, 2... Support tool pusher, 3... U bolt, 4... Nut, 5... Piping, 6... Base material.

Claims (1)

[Claims] 1. In a small-diameter piping support device for nuclear power generation equipment, which consists of a U-bolt, a piping support, and a tightening nut for supporting and restraining the piping, the U-shaped piping support prevents heat in the circumferential direction of the piping. A pipe support that is made of an elastic material that can bend in response to expansion, relieves thermal stress in the pipe, allows axial thermal expansion, and has a vibration prevention function.