Does the entire U-tube need to be pressure-tested?
Thread Content
There is a U-tube heat exchanger now, with the U-tubes being made up of entire tubes that have been bent. Is it still necessary to test each tube individually for pressure? 1. If not, why? 2. If so, what pressure level should be used – 1.5 times the design pressure or 2 times the design pressure?
1. It is needed. 2, which is at least 1.25 times the design pressure; in practice, 1.5 times is often used.
We conduct pressure tests; one reason is that the tubes have undergone cold working, and the other is that it is difficult to replace U-shaped tubes in case of leakage. The test pressure is generally also set at 2 times the design pressure.
Pt=1.25P /t is required; 1.5 times can be chosen.
All heat exchange tubes must undergo pressure testing after processing, with the test pressure generally being twice the design pressure; pressure testing is also required once the entire unit has been assembled.
If the heat exchange tubes are purchased as fixed-length tubes without welds in between and have been pressure-tested before leaving the factory, no further pressure testing is required prior to assembly； However, all units that have undergone assembly processing must undergo pressure testing, with the test pressure being twice the design pressure; pressure testing is carried out according to the requirements in the drawings once the entire unit is assembled.
Where did you buy your U-shaped heat exchange tubes? Were pressure tests and flaw detection performed on them before they left the factory? If they have already done it before the equipment leaves the factory, then all you need to ensure is that a pressure test is carried out on the equipment before it leaves the factory and that everything is fine! If they weren’t pressurized before leaving the factory, then you must pressurize them now! For the heat exchange tubes (U-type) produced by our company, all the tests specified by standards are carried out before they leave the factory; thus, customers can simply install them once they purchase them!
A hydrostatic test is necessary; generally, 1.25 times is sufficient..
Is cold bending prone to cracking? Why does GB151 state that \"U-tubes should not be hot-bent\"”
After U-tube formation, a single-pressure test is generally carried out, mainly because it is difficult to replace the U-tubes in case of leakage after the heat exchanger is assembled. If you’re not bothered by the hassle of changing the tube, you don’t have to do it either. The test pressure is generally taken between the equipment’s hydrostatic test pressure and twice the design pressure. There are no strict requirements. The 2-fold design pressure is derived from the test pressure of the spliced pipe. “U-tubes should not be bent hotly” because there is a risk of them becoming flattened
For those that require pressure testing, 1.25 to 1.5 times the pressure
A single-piece hydrostatic test shall be conducted at a pressure of 2 times the design pressure
The test pressure is twice the design pressure
After the entire U-shaped heat exchange tube is formed, the common practice of manufacturers is to conduct a hydraulic pressure test at twice the design pressure if such a test is specified in the drawings or technical specifications; otherwise, no such test is carried out. The splicing pipes must undergo a hydraulic test in accordance with the requirements of the Code.
Wuhan Ruishi Tong offers light-tube pressure testing quick connectors, which are safe and fast
http://v.youku.com/v_show/id_XNzQ2NzE2Njk2.html?firsttime=0 Share a video for everyone’s reference