Engineering design, engineering pressure issues
Thread Content
I have a question to ask our senior colleagues. We commissioned a **reputable design institute to carry out an engineering design, and the details of that design are as follows: 1. The pressure specified for the absorber in the design is 0.14 MPa, but why was the pressure rating of the gas pipeline connected to it set at 2.5 MPa, instead of 1.0 MPa (since 1.0 MPa is greater than 0.14 MPa)? (The absorbent liquid is water, and the main component of the gas phase is hydrogen.) 2. If a pressure test is conducted after construction, can the pipelines and the absorption tower be subjected to a hydraulic test simultaneously? If so, should the pressure for the hydraulic test be based on the design pressure of the tower or that of the pipelines? I would like to express my gratitude here.
1. If it is considered inappropriate, it is still necessary to consult the design institute and request a clear answer – (is the material the same?) ) 2. The pressure of the pressure testing system shall not exceed the maximum allowable pressure of the components in the system; the pressure testing procedure shall be formulated based on this principle
The nominal pressure of the pipeline can be high, but it cannot be low. Personally, I think it’s fine to use 2.5, and it’s also fine to use 1.0; of course, design firms tend to prefer larger values
1. Hydrogen pipelines belong to SHB pipelines, and their nominal pressure should not be lower than 2.0 MPa (GB50316); when the JB system is used, the nominal pressure of such pipelines should not be lower than 2.5 MPa. Therefore, it is reasonable to choose 2.5 MPa for the design. 2. During pressure testing, the pipeline and equipment are separated, with blind flanges added at the connection points. Otherwise, the equipment will be damaged when the pipeline pressure test pressure is 3.75 MPa.
The last edit to this post was made by zero229 on 2011-7-19 at 10:50. I completely agree with the first point: the pressure rating for hydrogen must be no less than 2.0 MPa; if a value of 1.0 is chosen, it simply indicates that the design team’s competence is poor. Regarding the second point, the original poster did not make their meaning clear. You mentioned pressure rating earlier, and design pressure later; these are two completely different concepts. The pressure used in water pressure tests is determined primarily by the design pressure and design temperature.
Which clause in GB50316 contains the provision you mentioned? (Hydrogen pipelines belong to SHB pipelines; the nominal pressure should not be lower than 2.0 MPa?) ）