PRV vs. Vapor space Riser for Liquid full 2" hexane piping?
PRV vs. Vapor space Riser for Liquid full 2" hexane piping?
(OP)
Our plant utilizes hexane in our processes. We had an incident with a liquid full 2" line overpressuring due to thermal expansion of the hexane in the blocked in system. The result was gasket failure at the flange.
Now I am evaluting a new 2" piping layout that could have liquid full conditions, full sun exposure, blocked in by valving. One solution is a PRV. Can we use a stand pipe or riser say 4-6 feet tall with a fixed cap or valve with blind on top ( similar to a high point bleed) as a safety vapor space so as to avoid a true liquid full condition and potential failure.
I am finding little techinal data on such a "riser" vs. PRV. It is not always suitable to use PRV since we do not have a flare line to dump to in every case. Any suggestions on how to approach. Calculations for the riser pipe for vapor space seem difficult to find.
Now I am evaluting a new 2" piping layout that could have liquid full conditions, full sun exposure, blocked in by valving. One solution is a PRV. Can we use a stand pipe or riser say 4-6 feet tall with a fixed cap or valve with blind on top ( similar to a high point bleed) as a safety vapor space so as to avoid a true liquid full condition and potential failure.
I am finding little techinal data on such a "riser" vs. PRV. It is not always suitable to use PRV since we do not have a flare line to dump to in every case. Any suggestions on how to approach. Calculations for the riser pipe for vapor space seem difficult to find.





RE: PRV vs. Vapor space Riser for Liquid full 2" hexane piping?
RE: PRV vs. Vapor space Riser for Liquid full 2" hexane piping?
Arn't the real solutions a relief valve in the proper locations, adding a vent or drain system, perhaps combined with a higher pressure rating for the system and ensuring that your joints make up properly.
"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.liv