My experience is in oil refining where there are streams at high pressure and temperature with high concentrations of H2S and none of the equipment was classified as lethal service. The only time I have ever seen it applied was in a plant for destroying chemical weapon mustard agent and when...
4 x 150,000 BBL IFR tanks are proposed for a new methanol plant. Is nitrogen blanketting required for the vapor space or are circulation vents sufficient?
As I recall, API 12J is just a tank with minimal internals so pressure drop should be small <1 psi if the nozzles aren't undersized. Add a demister and the drop goes up slighty. Add a filter coalescer and you start to add real pressure drop.
The NHT and CRU will generally be purchased together because you will need a naphtha splitter. In this flow range a semi regenerative scheme will be the most economic.
yield will be about 90%. Pay attention to product spec. Benzene and aromatics may be a problem.
There are modular fabricaton...
This is not unusual. I have seen 30 minutes. The time allows pumpout of the drum at a reasonsible rate to a slop tank. If there is a two phase relief then the answer is obvious. Even if the drum has only vapor relief there is usually condensation from saturated vapors after a reliving indident.
The Z factor in Hysys is 0 for a saturated vapor. If you move away from the saturation point, ie raise the temperature a bit, a degree or two, then then Hysys should report the Z factor.
If the valve relieves, cooling water has to flow through the exchanger to discharge. This is almost always safer than no flow through the exchanger. But if the relieving case is when the cooling water is blocked in, it probably does not matter whether the PSV is on the supply or return.
Hopefully, your liquid will remain in the blowdown vessel. If you don't have a dynamic simulator then run successive flashes at about 1-2 minutes interval. You should be trying to reduce pressure by half in 15 minutes. Calculate the mass removed during the interval, recalculate the liquid...
Cost for modularized refinery is $1000/bbl ex works. Needs to be transported, installed and hooked up. Does not include u and o. 35,000 bpd used refinery has 11' id atm column.