Compensator installation test

Bellows expansion joint and the pipe support installation method as shown in the above, during the installation process must agree to comply with.

Pipeline in the phenomenon of corrugated expansion joint tensile testing process will often happen, there was a problem in general pipeline pressure test there are three main types:

1. Due to improper piping temporary support, or piping fixed bracket set is not reasonable, lead to support damage, causing bellows excessive deformation and failure;
2. Bellows expansion joint design when considering the stress or displacement of the safety margin is not enough, when the pipeline pressure testing corrugated pipe buckling deformation failure;
3. Manufacturers cut corners in the process of manufacturing expansion joint production, product quality problems.

In many cases, of which the above (1) is the main cause of the expansion joint tensile, according to < < industrial metal pipeline engineering construction and acceptance specification > > GB50235-97, pressure test in section 7.5, the first paragraph 7.5.2.3: in order to prevent the expansion joint in the process of pressure testing due to the role of the pipeline axial tension tensile deformation, expansion joint setting temporary restraints on the pipeline.And often occur in the process of actual installation bracket set unreasonable, even there is no fixed support or temporary support.

Reasonable fixed set of piping, is to ensure that the necessary condition of corrugated compensator function choice of the piping system for pressure thrust without restricting expansion joint, corrugated tube is the basic principle of piping fixed support?

1. Pipe blind side must set fixed support
2. Medium flow direction change must be set at a fixed support
3. Branch pipe and variable diameter must be set fixed support
4. Two corrugated compensator with the valve must be set between the fixed support

1, before installation, should check the corrugated compensator expansion joint type, specification and pipe support configuration must composite design requirements.
Section 2, with the expansion of the inner tube, attention should be paid to make the lining tube direction is consistent with the flow direction of medium (according to the flow of expansion joint sign installation).Plane Angle hinge rotating screen to type expansion joint shall be consistent with the displacement of the plane.
3, the need for "tight" cold expansion joint, the prestressing of auxiliary components, should be in the expansion joint after predeformation dismantled.
4, piping should be removed immediately after installation on the expansion joint is used as the installation of auxiliary positioning transportation protection and fasteners, and according to the requirements of design limit device will be dispatched to the location of the regulations, make the piping in the environmental conditions to full compensation.
5, in addition to the design requirements of pretension pressure or "cold" tight predeformation, corrugated pipe deformation method is strictly prohibited to adjust the pipeline installation deviation, so as not to affect the normal function of the expansion joint, otherwise it will reduce its service life and increase piping components, equipment, and supporting the load.
6, expansion joint all the activities of the components shall be external components are jammed or limit their activities as usual.
7, the installation process does not allow welding slag splash into the panel lines tube surface and make corrugated pipe by other mechanical damage.
8, for the expansion of the gas medium section and its connection pipe, a water pressure test, whether you need to consider when water filling of expansion joint takeover of adding temporary support to bearing.
9, water pressure test must be pure water, no corrosion, and control the content of chloride ions in the water is not more than 25 PPM.After the hydraulic pressure test, as soon as possible as bellows in water, and promptly put the inner surface of the wave shell blow dry.
10, pipes, it is better to neutral, in the absence of other methods to ensure straight cut length after laying pipe can be used again to ensure that the installation of expansion joint method.
11, must pay attention to is that the expansion joint is not absorb torque, so when installing expansion joint, do not allow the expansion joint is reversed.
12, expansion joint all the activities of the components shall be external components are stuck or limit their activities at normal operation.
13, insulation should be done outside the expansion joint on the case, may not be done directly on the corrugated pipe.Insulation materials shall not adopt any chlorine.
14 and the installation process does not allow welding slag splash to the surface of the corrugated pipe and other mechanical damage to bellows.
15, bracket must comply with the design requirements, forbidden before stent were installed in the pipeline pressure testing, so as not to pull expansion joint.
16, expansion joint allowed no more than 1.5 times the nominal pressure test system.
17, equipped with expansion joint in the operation of the pipeline, valve opening and closing to gradually, in order to avoid rapid changes in temperature and pressure in the pipeline, bracket or expansion joint damage