The heating semi-pipe of the reaction kettle often leaks; how to deal with it?
Thread Content
The heating pipes in the reaction vessel often leak; the heating steam pressure is 0.6 MPa and the temperature reaches 180 degrees Celsius. Sand holes particularly appear at the welds, requiring the removal of the entire external insulation layer. The welding repairs are cumbersome: cooking, isolation with blind flanges, nitrogen purging, removal of the insulation, and then welding. How can we ensure no leaks over a long period of time?
The material of the half-tube is different from that of the inner liner, so leaks are normal
First, it needs to be inspected. Second, it depends on your specific situation: how many times has leakage occurred, does this happen frequently? Is there a problem with the welding materials? If there is a problem, then re-welding is necessary; otherwise, the issue won’t be resolved fundamentally, and it will remain the same forever
There are likely issues with the manufacturing process. Firstly, the materials used for the half-tube and the reaction vessel are different, and the welding materials as well as the quality of welding lead to poor weld quality. Given that a steam pressure of 0.6 MPa is not high, steam should not cause corrosion of the welds; therefore, the frequent leaks can only be attributed to the differences in materials and the poor quality of welding.
It can be made with a jacket; this way, the heat tracing effect is ensured, and the number of welds is reduced, thereby decreasing the likelihood of leaks
After it’s completed, isn’t it necessary to apply a design pressure of 1.25 times the normal value for a hydrostatic test? Half tube
If it is insisted to use a half-pipe, the repair welding of the half-pipe must be carried out by qualified pressure vessel welders. Manufacturers generally do not have such personnel. Generally, it’s due to the wrong welding material, incorrect welding method, or poor welding skills. It is recommended to have the welding done by the manufacturer of the container; after welding, perform surface inspection and hydrostatic testing. If everything is satisfactory, there will be no more leaks (except due to corrosion). At a pressure of 0.6 MPa, welding is very easy. I agree with the suggestion from floor 6; we should use jacket heating from now on. We are a container manufacturing manufacturer; we welcome cooperation!
If jacket heating is used, the thickness of the shell and other parameters will change; it’s better to implement more reasonable control over the welding methods and processes
Frequent leaks are clearly due to improper welding techniques or poor welding quality. Even after several attempts at correction, the customer has not asked the manufacturer to replace the equipment. If it were our equipment, we would have replaced it for the customer long ago
Half-tube leak detection is indeed quite troublesome. But by doing a good job of welding and inspection, the likelihood of leakage should **decrease**. 1. Ensure proper welding by using manual welding to achieve at least 2 weld layers. 2. Conduct a leak test; if possible, use water for this purpose. Airtightness is also acceptable; during inspection, use gauze dipped in soapy water to wipe along the welds, which makes it easier to detect large pores. Alternatively, if possible, treat the surface before ensuring airtightness. Finally, the inspectors must be responsible.