Maximum pressure difference for valve closure
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How is the maximum pressure difference for closing the valve determined? Is it the maximum pressure before the valve?
It is basically determined based on the design pressure of the pipeline
When there is no leakage in the valve body, it’s basically as the technician upstairs said – the calculation can be done based on the design pressure of the pipeline
The maximum closing pressure difference is an important parameter in the selection of valve actuators. The maximum closing pressure difference is not necessarily determined based on the pressures in pipeline systems; rather, it should be the maximum design pressure of the process. For example, if there is a compressor ahead, its maximum outlet pressure represents the maximum design pressure of the process, which is also the maximum closing pressure difference for the valve. This value is generally specified in the technical specifications. If the maximum pressure limit of the compressor is 0.65 MPa, and the pipes are rated according to American standards at 150 LB (2.0 MPa), then the pressure rating of the valve body is the same as that of the pipes, namely 150 LB. However, the selection of the actuator can be based on a maximum closing pressure difference of 0.65 MPa; a safety factor of 1.5 is applied, and the selection is made based on 0.975 MPa, to ensure that the valve can open and close properly under the maximum closing pressure difference.
This post was last edited by Xiāoyáo Ténglóng on 2019-1-29 at 13:47. Great masters, please accept my apologies… I also don’t agree with choosing the maximum pressure of the pipeline; it’s more reliable to use the maximum pressure of the process. Anyway, when I fill out the specification sheet, I always enter the maximum process pressure specified by the process requirements.
Use common sense to think about it – it should be the maximum pressure in the process upstream of the valve that matters...... That’s because downstream of the valve, various problems can occur; for example, the pipe downstream of the valve might crack, it might burst due to freezing, or ants and mice might dig holes in it...... It’s disgusting stuff like this that can happen suddenly, without any clear reason......