Hello everyone I have listed below some steps for calculating preliminary psv inlet/outlet size for blocked flow for single phase gas
Blocked flow case for gas …conventional PSV with set pressure at 150 psig. Constant superimposed backpressure is 2 psig.
- Simulate the gas stream at relieving pressure (1.1 x Set Pressure) and relieving temperature and obtain properties from HYSYS
- Check inlet line size for pr. Drop to be <= 3% of set pressure
- Use a valve in HYSYS and drop pressure from 1.1 x Set Pressure at upstream to 10% of built up back pressure + constant superimposed backpressure (2psig here). Hence flash from 165 psig to 17 psig.
- The properties obtained from HYSYS at 17 psig is above step is to be used for outlet line sizing
- Check tailpipe size for 0.7 Mach and rhov2 criteria and size appropriately
Please provide ur comments on this thanks