How to determine the setting pressure of a safety valve when both the design pressure and the maximum allowable operating pressure are present?

The setting pressure of the safety valve should be lower than the design pressure, right?

You are in the manufacturing department and process according to the drawings; this data has nothing to do with the manufacturing factory, as the values on the drawings are correct.

According to the description in the question, the design pressure is 0.5 MPa, the maximum allowable operating pressure is 0.6 MPa, and the set pressure of the safety valve is 0.55 MPa. According to Clause B.4.7 of GB/T150.1, the setting pressure shall not exceed the design pressure. According to this regulation, 0.55 MPa is less than 0.6 MPa, so it meets the requirements. Therefore, in this case, there is no need to change the set pressure to ≤ the design pressure. Setting the set pressure at 0.55 MPa is reasonable. .

You need to read the standards carefully and not take things out of context; take a look at what GB150.1.B3.1 says “When the maximum allowable operating pressure is indicated on the design drawings and nameplate, the maximum allowable operating pressure of the container may be used in place of the design pressure; the same applies hereafter”

This post was last edited by wanlirn on 2023-6-28 08:28. It’s a good habit to ask questions on forums; otherwise, communicating in this way in real life would make people laugh out loud. What is the maximum allowable operating pressure? You don’t understand it

It depends on whether you conduct a airtightness test or not

Only the design unit has the right to modify its own design; if there are any questions, they can be raised with the client, who will then communicate with the design team. The manufacturing unit does not have the authority to alter the design； When the maximum allowable operating pressure is specified on the diagram, the set pressure can be higher than the design pressure, but it must not exceed the maximum allowable operating pressure. Remember not to alter the drawings that have already been reviewed, unless design errors are found. If the design requirements are overly stringent and uneconomical due to reasons such as inadequate consideration, no changes should be made unless the client requests it. When you become complacent about having identified ways to reduce costs, there may be risks arising from factors that you haven’t taken into account or from an insufficient understanding of the standards.

Any pressure up to the maximum allowable working pressure is fine; you didn’t read carefully. It is recommended that you set it according to the maximum allowable operating pressure.