Bulk liquid CO2 storage question

[Seangoloid]

I vaguely remember something I heard a few years ago about minimum PSI on a bulk liquid CO2 tank before having to clean and sterilize it again.
Basically, the theory was that if the pressure in the bulk tank dropped to a certain level (still positive pressure), then the tank would need to be completely blown down, cleaned, and sterilized before a refill.
Anyone else ever heard of this?

Thanks in advance.
Cheers!

[gitchegumee]

Never heard of that. Then again, your pressure should NEVER go down. As liquid boils, it is supposed to keep up the pressure. Almost all bulk tanks have two power circuits on them; 1) a compressor to pull vapor, compress it, discharge heat via a condenser, and return cooled CO2 to the tank to keep the CO2 in liquid form; and 2) a heater to boost tank pressure if you pull CO2 quick enough to lower the pressure (and temperature). Besides, your bulk supplier is supposed to keep the tank full. You shouldn't let it get near empty. If you are concerned, then put a pressure sensor and a solenoid valve to shut down flow on a near empty tank. Good luck!