Selection of test pressure for simple pressure vessels
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Dear experts: I have a question. Our company is currently designing an air storage tank that falls under the definition of a simple pressure vessel; however, it cannot be produced in batches – only one unit is manufactured at a time. This applies to the provisions for simple pressure vessels in TSG 21, Note A. As stated in Note A, simple pressure vessels are generally manufactured in batches. When a small quantity is involved and batch production is not carried out, it should be handled in accordance with the general procedures for batch production of simple pressure vessels. When batch production is not carried out due to a small quantity, it shall be designed and manufactured in accordance with GB 150 (no type testing is required), and its use shall be managed in accordance with 7.1.11 of these regulations. 】 Designed and manufactured in accordance with GB150 – is it also necessary to comply with the requirements regarding the design of simple pressure vessels outlined in TSG21? (P27) For example, the test pressure for pressure tests is determined according to GB150 as 1.25 times the design pressure multiplied by the temperature coefficient; for simple pressure vessels covered by the Large Volume Vessels Regulations, it is 1.5 times the design pressure. Do we also need to meet the requirements for large capacity specifications here? Please ask the experts in this forum to help answer it.
One unit is designed and manufactured in accordance with the standards for ordinary pressure vessels, TSG 21, GB/T150
The customer requests that it be managed as a simple pressure vessel. Can it be designed and manufactured according to tsg21gb150 with simple management?
It is designed and manufactured in accordance with tsg21gb150, following simple management principles, as it belongs to the category of simple pressure vessels. My personal understanding.
Is it difficult to use a test pressure of 1.5 times the design pressure?
TSG21 needs to be met. TSG21 is designed for the use of pressure vessels, while 150 is more oriented toward design.
This post was last edited by wx_Catherine_Mi on 2020-5-15 12:35 to learn* from it. In my opinion, one is design and the other is production; they are not contradictory
First of all, I don’t see what the difficulty is in using a value that is 1.5 times the design pressure; according to the calculations, it’s not possible to reach 1.5 times that value, as 1.5 times actually represents a high requirement. Secondly, TSG21-2016 is a technical specification that is mandatory to follow, while GB/T150-2011 is a recommended national standard; its legal status is lower than that of a technical specification, and the technical specification takes precedence. However, this technical specification also references GB/T150, so that standard is also mandatory to comply with. Third, GB/T150-2011 requires that the pressure for the withstand test be in line with the design specifications. Finally, where required by multiple laws and regulations, it is recommended to meet all of them; if it is not possible to meet them all (which generally does not happen), the one with the higher regulatory hierarchy shall take precedence.