[HWY36]

Originally Posted by Gray Wolf

https://dsps.wi.gov/sb/docs/sb-CodeD...ppx85to106.pdf

Above is a link to ASME Section VIII, which outlines pressure relief requirements in UG 125 through 137.

Pressure Relief Devices/UG-125 General

(a) All pressure vessels within the Scope of this Division, irrespective of size or pressure, shall be provided with pressure relief devices in accordance with the requirements of UG-125 through UG- 137.

NFPA-58 definition of pressure relief devices and valves for LPG service.

https://www.nfpa.org/assets/files/ab.../58-98-pdf.pdf

Pressure Relief Devices:

A device designed to open to pre-vent a rise of internal fluid pressure in excess of a specifiedvalue due to emergency or abnormal conditions.

Pressure Relief Valve.

A type of pressure relief device designed to both open and close to maintain internal fluid pressure.


If you look at their ad, they are calling it a Pressure Relief Valve: https://www.opensourcesteel.com/prod...d-solvent-tank

If they are selling this for LPG service, they ostensibly should meet the requirements for that service.

Thank you for the info. I will try and figure out a diplomatic way to let them know that IF what they're selling is designed to do what they claim, they are endangering people's lives. Given their initial response, I don't expect a warm reception.

After ALL the gas blew off (well after), I opened the return valve, coming from the heat exchange-going to the recovery tank to make sure that it was indeed the PRV that failed. It was. The PRV was still open and any gas that I vented into the recovery tank spewed out of the PRV.

[HWY36]

https://www.opensourcesteel.com/coll...e-relief-valve

This is the PRV that Open Source Steel sells. I believe it is the exact same one that comes on the 100# tank. Anyone know if this is designed to reclose or just keep endlessly releasing pressure?

[Gray Wolf]

That looks to me like a pressure relief valve, as it is labeled, which is supposed to reseat and turn off once the pressure has dropped. A pressure relief device stays open.

If it is actually a device it is mislabeled.

It is also a very cheeep valve for that application. Not one that I would use.

[IdahOg]

To avoid a situation similar to highway 36; What if I plumbed the PRV on my main recovery tank to an access empty recovery tank to create a backup safety location for gas to recover. Im curious any thoughts on that kind of safety setup. Also should i put that extra recovery tank under negative pressure or would that negative pressure potentially pull on the PRV releasing gas from main tank ?

[Gray Wolf]

Originally Posted by IdahOg

To avoid a situation similar to highway 36; What if I plumbed the PRV on my main recovery tank to an access empty recovery tank to create a backup safety location for gas to recover. Im curious any thoughts on that kind of safety setup. Also should i put that extra recovery tank under negative pressure or would that negative pressure potentially pull on the PRV releasing gas from main tank ?

While that sounds like a good idea, and I originally designed a system that way, there is no guarantee with such a set up that it won't simply over pressure both tanks, so it was rejected when I went for certification to ASME.

[HWY36]

Originally Posted by Gray Wolf

While that sounds like a good idea, and I originally designed a system that way, there is no guarantee with such a set up that it won't simply over pressure both tanks, so it was rejected when I went for certification to ASME.

Wouldn't two #100 tanks be more likely to disperse 150 PSI because there is more volume to hold the pressure?

I observed a shit ton of water in the bottom of the tank when it was done gassing off. Will that have any drastic effects on PSI?

[Gray Wolf]

Originally Posted by HWY36

Wouldn't two #100 tanks be more likely to disperse 150 PSI because there is more volume to hold the pressure?

I observed a shit ton of water in the bottom of the tank when it was done gassing off. Will that have any drastic effects on PSI?

If the second tank were large enough it clearly would work, but there needs to be protection in case it isn't large enough to keep the peak pressure low enough.

Perhaps a second tank to catch the over pressure, but a slightly higher pressure release on that tank as well.