Can half-pipe jacketed vessels be subjected to air pressure tests?
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Recently, a customer came to our company for FAT. Our jacketed vessel had already undergone a hydraulic test and proposed a pneumatic test. After consultation, we agreed to their request and maintained the pressure with a design pressure of 0.4Mpa. I have never done this before. When I checked the solidification and capacity regulations, I found the following regulations. In TSG2016 3.2.2.2 Requirements for welded joints: The welded joint design of jacketed pressure vessels, if it is a vessel that requires air pressure test or gas-liquid combined pressure test, should be a fully welded structure. I'm wondering if this one includes the fillet weld between the half pipe jacket and the barrel. Are there any friends who understand this?
Generally, the inner diameter of the half-pipe jacket is less than 150, and the jacket does not need to consider the requirements of the solid content gauge.
For the air pressure test of half-pipe jacketed vessels, since the weld between the jacket and the cylinder usually cannot achieve a full-penetration structure, the test is carried out in accordance with the TSG2016 "Special Equipment Safety Supervision Regulations" 3.2.2.2 According to the regulations, air pressure testing cannot be done. The full penetration structure here refers to the welding method in which the two parts of the weld are melted into a whole in the welding area. In most cases, the fillet weld between the half pipe jacket and the cylinder cannot achieve full penetration. So your understanding is correct. This provision can indeed include the fillet welds between the half-pipe jacket and the cylinder. Containers that are to be subjected to air pressure tests or gas-liquid combined pressure tests should be of fully welded structure. In actual applications, the testing method needs to be decided based on the specific container structure design and usage requirements. If the customer insists on performing air pressure testing, the design of the welded structure may need to be reconsidered. .
Air pressure and air tightness tests are two different things. Jacketed coils cannot be subjected to air pressure tests no matter what. This is determined by the structure. It can only be made airtight. .
By the way, I always forget that the half-pipe jacket is less than 150, so there is no need to follow the solid capacity regulations. Are there any other regulations that limit the pressure test of the half-pipe jacket? Including test type and medium.
Users may not understand very well and think that a pressure test is necessary to remove steam from the shell. No air pressure test is required and GB/T150.1-2011 can be used.
The fillet weld between the half-pipe jacket and the cylinder is generally an incompletely welded structure. There is a certain risk in air pressure testing if there is an incomplete fillet weld. This is not an unsupervised issue. Of course, the risk does not mean that it cannot be done. There are no regulations restricting the pressure test of half-pipe jackets.
Since there are no clear regulations, it should be said that there is a risk, but if the test is carried out according to the air pressure test pressure of GB150.1, there should be no big problem.