steveb1111
Chemical
- Aug 4, 2005
- 21
We are installing a hot gas bypass to protect centrifugal compressor from surge following ESD. The design includes two 24-inch check valves immediately downstream of the bypass line to minimise the compressor discharge volume that needs to be depressured. The required opening time of the bypass valve is about 0.5 second. We have spent a lot of expense and effort to minimise the opening time of the bypass valve using dynamic simulation, but little attention has been paid to the closing time of the check valves.
If we assume the check valves close intantaneously once flow reversal occurs everything is OK. For 24-in check valves, I'm doubtful this is realistic. However, I'm struggling to find any data on closure times for check valves and the simulation indicates that closing time is critical. A closure time of more than 0.2 seconds is predicted to result in surge.
Does anyone have guidance on the design of hot gas bypass systems and their associated check valves?
If we assume the check valves close intantaneously once flow reversal occurs everything is OK. For 24-in check valves, I'm doubtful this is realistic. However, I'm struggling to find any data on closure times for check valves and the simulation indicates that closing time is critical. A closure time of more than 0.2 seconds is predicted to result in surge.
Does anyone have guidance on the design of hot gas bypass systems and their associated check valves?
