Notes for installation and pressure test of expansion joints
1. Before installation, check the type, specification and pipe support configuration of expansion joint of corrugated compensator must be combined with design requirements.
2. For expansion joints with inner liner, attention should be paid to making the direction of inner liner consistent with the direction of medium flow (install according to the flow direction sign of expansion joints). The hinge rotation screen of the planar angular expansion joint shall be consistent with the displacement plane.
3. For expansion joints requiring "cold tightening", auxiliary components used for pre-deformation shall be removed after pre-deformation of expansion joints.
4. After the installation of pipe system, the auxiliary positioning mechanism and fasteners used for installation of transportation protection on expansion joints shall be dismantled immediately, and the limit device shall be adjusted to the specified position according to the design requirements, so that the pipe system can be fully compensated in environmental conditions.
5, in addition to the design requirements of pre-tension or "cold tight" pre-deformation, it is strictly prohibited to use bellows deformation method to adjust the installation of pipe deviation, so as not to affect the normal function of the expansion joint, otherwise it will reduce its service life and increase the load of pipe system, equipment and supporting members.
6. All moving components of the expansion joint shall not be stuck by external components or restricted to normal operation of the moving parts.
7. During the installation process, welding slag is not allowed to splash on the surface of the panel corrugated pipe and cause other mechanical damage to the corrugated pipe.
8. When conducting hydraulic pressure tests on expansion joints and their connecting pipes used for gas media, it is necessary to consider whether temporary supports should be added to the nozzles of expansion joints to bear the load when filling water.
9. The water used for hydraulic test must be pure and non-corrosive, and the content of chlorine ions in the water should not exceed 25ppm. After the hydrostatic test, the water in the bellows should be drained as soon as possible, and the inner surface of the wave shell should be blown dry quickly.
10. The pipe is better for neutral. When there is no other way to guarantee, the straight pipe can be laid, cut off the pipe of equal length, and then install expansion joints.
11. It should be noted that the expansion joint does not absorb torque, so when installing the expansion joint, the expansion joint is not allowed to be torsional.
12. All moving components of expansion joints shall not be stuck by external components or restricted to normal operation of their moving parts.
13. The insulation layer shall be made on the outer protective sleeve of the expansion joint, and shall not be directly made on the bellows. Insulation materials containing chlorine shall not be used.
14, during the installation process, welding slag is not allowed to splash on the surface of the bellows and other mechanical damage to the bellows.
15. The support must meet the design requirements. It is strictly prohibited to test the pressure in the pipeline before the support is installed, so as not to damage the expansion joint.
Expansion joints shall not exceed 1.5 times the nominal system pressure test.
17, in the operation of the pipeline with expansion joint, the valve should be opened and closed gradually, so as to avoid sharp changes in the temperature and pressure in the pipeline, causing damage to the support or expansion joint.