Issues with pressure testing of tower vessels during on-site welding of newly installed units! ! ! ! ! !
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Due to the relatively large size of the equipment, it was delivered to the site in sections by the manufacturer and then assembled and welded on-site; this process has now been completed. I would like to ask: does anyone among you know how pressure testing is carried out after the equipment has been assembled and welded on-site? Is it necessary to measure water pressure? Is it implemented in strict accordance with SH3542-2007? ? Please give me some advice! ! !
Our long-standing practice has been that, if the equipment is not very tall (under 30m), it is positioned after ground pressure testing; for those that are difficult to lift in one go, 100% non-destructive testing of the welds can be used as a substitute for hydrostatic testing.
The tower is 45 meters tall. It has now been installed in place, and the interior components are being fitted, but will a hydrostatic pressure test be carried out in the end? ? ?
11. A hydrostatic test must be carried out; if it is a pressure vessel, an inspection and certification are also required. The certificate issued by the manufacturer is different from the one issued by the local boiler inspection agency after on-site assembly, and the on-site assembly must be conducted by the boiler inspection agency located at the site. 2. During testing, foundation settlement also needs to be measured
A pressure test is necessary. When conducting this test, the required design pressure should be taken into account; if it is less than 0.6 MPa, a pneumatic test can be carried out, while if the pressure is higher than 0.6 MPa, a hydraulic test is required. During a hydraulic test, it is important to monitor any settlement of the foundation. The pressure test is carried out after the internal components have been installed. Remember: A pressure test must be carried out, even if the welds pass the 100% inspection, as their strength may not meet the required standards.
If the equipment to be welded is a pressure vessel, it is necessary to go to the local technical supervision authority to obtain approval before starting welding. Afterwards, the inspection agency will come to the site for supervision, as pressure testing falls under Category A inspection requirements, which means that someone from the inspection agency must be present to supervise the process. Without passing this inspection by the agency, further progress cannot be made; therefore, it is essential to carry out this procedure. Those who have experience in such construction work are likely familiar with the specifics of pressure testing. If it does not belong to the category of pressure pipelines, hydraulic testing is still required according to regulations. I believe it is unreasonable to use radiographic testing as a substitute for pressure testing, as hydraulic testing not only checks the quality of the welds but also examines the material of the equipment itself. Of course, if the supervisor and the client agree to using radiographic testing instead of pressure testing, that is acceptable, but the contractor must still keep written records of the process.
It must be done: after the internal components are installed, the manhole should be sealed, and then a hydrostatic test should be conducted, while keeping thorough records of the settlement observations
Yes, it can be done, but the boiler inspection agency must be notified