Technical requirements for installation of compressed air pipeline in clean workshop

1. pipes, fittings and valves are inspected and checked correctly according to the design requirements before they can be installed.

 

2. all pipe supports and hangers are supported by finished products and hangers, and the specific quantities are calculated by the contractor himself.

 

3. the pipe used for flange connection can be installed two times. After the flange is welded with the pipeline, it will be removed, corrected and cleaned again.

 

4. in the layout of the pipeline, the small pipes, including the instrument pipe, which are determined by the site construction, should be arranged neatly and properly. After the installation of other pipes, the installation should be carried out according to the requirements of the project and the design documents.

 

5. the pipeline should be well protected during the installation process, and gloves, bolts and welding materials must not be allowed to fall into it.

 

6. all corroded parts must be treated with antirust and appropriate Antirust Coatings, and at the same time, electrolysis due to direct contact of different metals should be prevented when installation work is carried out.

 

7. the pipeline should be fixed with brackets, especially those with flexible joints and pipes that are not allowed to be loaded.

 

The distance between the 8. maximum pipe supports is not more than 5 meters. Actual layout and details are provided by design requirement and parameter list, submitted to project management and owner approval.

 

The 9. non thermal insulation power pipeline support generally adopts the arc tube, but in order to prevent the accidental falling off of the pipe caused by the radial displacement in the horizontal direction, a sliding support should be set at about 24m every other.

 

10. the piping supports, supports and parts are painted with antirust paint two times after removing rust and dirt.

 

The welding of the 11. hangers should be welded by qualified welders, and there should be no defects such as missing welding, under welding or welding cracks. When pipe and bracket are welded, there must be no phenomenon of biting and burning.

 

The welding of the 12. hangers should be welded by qualified welders, and there should be no defects such as missing welding, under welding or welding cracks. When pipe and bracket are welded, there must be no phenomenon of biting and burning.

 

13. the circumferential welds of the pipeline shall not be placed on the support, and the edge of the support shall not be less than 200 millimeters. The longitudinal weld of the welded steel pipe shall be oriented towards the direction of inspection.

 

14. when the compressed air pipe is threaded, each branch pipe should have a live joint near the maintenance parts such as threaded connections to facilitate maintenance.

 

15. the design of compressed air pipeline with pressure greater than 1.0MPa should be examined by sampling radiography after installation, and the ratio is not less than 5%, and the quality is not less than grade III.

 

When the 16. power pipeline is installed after the installation, the strength test should be carried out. When the pressure test is adopted, the pressure of the low pressure system is 1.15MPa, and the pressure of the high pressure system is 1.61MPa. The test medium is dry and clean air. It is necessary to agree with the construction unit before the test. At the same time, the safety protection and isolation measures should be well done during the test. Before the test, air must be used for pre test. When the test is tested, it should be gradually pressurized, when the pressure rises to 50% of the test pressure, if no abnormal shape or leakage is found, it continues to press the test pressure of 10% step by step pressure, and the pressure is 3min at each level until the test pressure. Then the pressure is 10min, then the pressure is reduced to the design pressure to be inspected, and the foaming agent is tested for no leakage.

 

When the 17. power pipeline is installed after the installation, the strength test should be carried out. When the pressure test is adopted, the pressure of the low pressure system is 1.15MPa, and the pressure of the high pressure system is 1.61MPa. The test medium is dry and clean air. It is necessary to agree with the construction unit before the test. At the same time, the safety protection and isolation measures should be well done during the test. Before the test, air must be used for pre test. When the test is tested, it should be gradually pressurized, when the pressure rises to 50% of the test pressure, if no abnormal shape or leakage is found, it continues to press the test pressure of 10% step by step pressure, and the pressure is 3min at each level until the test pressure. Then the pressure is 10min, then the pressure is reduced to the design pressure to be inspected, and the foaming agent is tested for no leakage.

 

18. the Contractor shall submit the pressure test plan before the pressure test to the project manager and the owner for approval.