How to implement prvs / burst disc for each vessel

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I have some questions regarding adding prvs or burst discs to a system. Also it would be good to have some useful safety information out there for having safe systems in bad circumstances for emergency personnel and anyone else nearby.

Regular wall mounted CLS 6" columns and 12" collection vessel. CRC is connected to the bottom of columns via stainless steel braided hoses. There is a 100psi prv on the collection and solvent tank.

My concern is adding prvs or burst discs for fire safety or if anything else happens. Trying to prepare for the fire season as it’s pretty bad around here.

Vented burst discs on the collection and solvent tank would be a no brainier since they aren’t vacuumed down very often.

I would just go with vented burst discs on all the vessels but I hear you should change them frequently because repeated vacuum/pressure cycles weaken them, not something you want failing randomly.

Would regular 1\4 inch 150psi prvs be adequate for each of the 6x48 columns? They seem to hold vac well enough.

The vessels never see over 75psi with gas at room temp under normal circumstances. The columns are never closed off during soak times for safety.

For a solvent tank I understand a regular 1/4 PRV doesn’t move adequate amounts of gas in a fire situation and can pose a risk of explosion. The pressure rating of the solvent tank is only 100psi. The plan is to get a higher rated solvent tank (250-350psi) since it’s used for 70/30i. Along with a little added nitrogen it doesn’t leave adequate headroom in the pressure rating for a burst disc to be used safely. Pretty much all the pressure rating is being used on a regular basis.

I might not be looking in the right places but I’m not seeing any NPT vented rupture discs.

Thank you and let’s be safe out there!

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Why would you do this? I never do this - then is something goes wrong you are beyond your tank rating and your fitting ratings and your gasket ratings… I try to use things at about 50 to 75% of their rating, especially since temperatures really change what’s happening.

Reading your post made me feel a bit uncomfortable about your safety plan. Apollo has 1/4 inch pressure relief safety valves that are NPT - but I don’t know that they are designed to safely vent flammable gasses into a fire situation. Here is a video that shows a tank on fire and the giant finger of god that shoots forth from the safety valve - so be mindful of where you direct its flow it so that it doesn’t kill people standing nearby or blow up other stuff.

I think perhaps you are not finding the rupture disks - because the intention would be to put the fire out and cool off whatever is nearby, reducing the pressure and keeping the rest of the flammable gas in the vessel. So you’d want a relief device that can “close” again - after the fire department has done its thing, yes?

So I’d stick with a PRSV of some kind. And make sure that where ever they are being installed was going to vent into a location/direction that wouldn’t harm people or make things worse. I always thought that burst disks are to prevent your tank from bursting or your fittings/spools sheering off and killing someone. I’ve never used them for flammable gas (cause then the room fills with a lot of gas until the tank is empty), and I agree they stop working after a bit, sometimes because people are rough with them and they are delicate. Other times because the activities you are using are rough.

Good luck with your project.

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