The difference between BDV and PSV
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This post was last edited by purplelov on 16:50, 1/9/2017. I would like to ask fellow experts: what are the differences between BDV and PSV in terms of applications and valve selection? Thank you all. For example, in a certain project, the BDV was used before the CPF inlet isolation valve; could someone help analyze this?
It seems to be the difference between differential pressure control before and after the valve and pressure control behind the valve.
I would like to ask you another question regarding the calculation of the outlet pipeline for safety valves. The specifications require that the pressure drop in the outlet pipeline be less than 10% of the set pressure, with the flow velocity in the branch pipes being less than 0.7 m/s and the flow velocity in the main pipe being less than 0.5 m/s. If the gas is compressible and a critical flow (1 Ma) is established at the outlet of the relief valve BDV, then the pipeline downstream of the outlet should also have a flow rate of 1 Ma. In that case, how can the requirement of below 0.7 Ma specified in the standards be met? (Valves and pipelines are usually considered based on their diameter.) Maybe I misunderstood; please enlighten me