Understanding of Clause B.1.5 in Appendix B of GB/T 150.1-2024
Thread Content
Hello, colleagues. Regarding clause B.1.5 in Appendix B of GB/T 150.1-2024: This appendix does not apply to containers used for storing cryogenic liquefied gases. How do everyone understand it? Understanding 1: Literally speaking, everything listed in Appendix B of GB/T 150.1-2024 does not apply to containers used for storing cryogenic liquefied gases (Question: If that’s the case, which standard should be followed regarding the relationship between the setting pressure of the safety valve and the operating pressure of the inner container when designing containers for cryogenic liquefied gases such as liquid nitrogen, liquid oxygen, liquid argon, and liquefied natural gas?) Should it still be decided arbitrarily by the designers themselves? ) Understanding 2: Only clause B.7.4.3 b) of the calculation section regarding the discharge capacity of safety valves in Appendix B of GB/T 150.1-2024 does not apply to containers holding cryogenic liquefied gases; the calculation of the safe discharge capacity for such containers is carried out in accordance with GB/T 18442.6-2019 ； For containers holding cryogenic liquefied gases, the relationship between the setting pressure of the safety valve and the operating pressure of the inner container shall still be in accordance with clause B.4.8 of Appendix B to GB/T 150.1-2024 (that is, the setting pressure of the safety valve shall be 1.1 times or greater than the operating pressure of the inner container). I would like to ask my colleagues to share their own understandings, the basis for their practical implementation, or the understanding of local inspection agencies regarding this clause Thank you
It is not applicable, but this does not mean that the standard cannot be followed; it’s just that applying this standard alone to liquefied gases is far from sufficient – calculations also need to be carried out in accordance with GB/T18442.6-2019. However, from a legal perspective, as long as the design documents are met, it is sufficient. The most common violation regarding safety valves is their installation in a 【vertical】 position; all technical specifications and standards related to the installation of safety valves require that they be installed vertically. Some design documents for low-temperature storage tanks do not specify vertical installation, and this is a situation in which both the design firms, manufacturers, and users violate the relevant regulations.
The key point is that customers ask us: Article B.1.5 of Appendix B to GB/T 1501-2024 clearly states that it is not applicable to cryogenically liquefied gas media; then why should the setting pressure of the safety valve be 1.1 times the operating pressure? Let’s find the basis for setting the safety valve pressure at 1.1 times the operating pressure. Could you help me figure out how to respond to the customer? The customer said that the 2011 version does not mention such a requirement; therefore, for frozen liquefied gases, the set pressure of the safety valve can be determined based on 150. However, with the 2024 version, this rule exists, so it’s no longer possible to use 150 as a reference. So should the designer decide it arbitrarily? Can I take as much as I want?
First, tell him: You have the expertise and qualifications; you can handle it on your own； Second, tell him that although GB/T150-2024 is a recommended standard, it is enforceable ； Third, tell him that regardless of the standard used, GB/T150 is the fundamental standard and will be cited in all cases ； Although the other criteria are somewhat complicated, the set pressure is simply the working pressure multiplied by 1.1, as long as this value does not exceed the design pressure or the maximum allowable working pressure.
Thank you for your reply; I share your understanding. But the customer insisted that clause B.1.5 of Appendix B to GB/T 150.1-2024 clearly states that it is not applicable to cryogenically liquefied gases, so why apply the requirements from Appendix B of GB/T 150.1-2024?
Why are you so stubborn? Don’t you understand what forced execution means?
GB/T150 is a fundamental standard among the harmonized standards; even when designing using other standards, they still refer to GB/T150. To date, no inconsistencies with GB/T150 have been found. Design cannot be based on the client’s whims; it must adhere to certain standards. I advise you to give up on pursuing this kind of work, as the risks are very high. You are acting in accordance with **laws and regulations; you can’t let some wealthy person dictate your actions at will. Working in this field not only involves high risks but also doesn’t allow you to earn any money.
Returning to the set pressure, it is fine for the set pressure to be 1.1 times the operating pressure; this is the standard practice everywhere. In the previous version, the range was 1.05 to 1.1 times. In any case, following GB/T150 is acceptable, and even if you follow foreign standards, they still need to meet the requirements of domestic standards. It was explained clearly earlier that \"not applicable\" here means the requirements are not sufficient; you need to raise them further, not lower them.
Customers question a 1.1 times factor simply in an effort to reduce costs; it’s wrong to sacrifice safety for profit. This represents the minimum standard for design, and there’s no need to go beyond that standard just to meet their demands.