Pressure in tank raising a little every day

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Hey guys . So I’m using 70/30 ntane and propane. Probably still some iso butane from before as well. Pressure was around 60 when I put 25 lbs in. Now it’s down to 8 lbs left and it’s at 80 I do n2 assist sometime but I’m always sure to purge it off. When i purge off the tank it’s straight propane. Should I be concerned?

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Mixes will eventually become richer in propane over time due to it being recovered first.

There’s a few threads about it.

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That makes sense. I was thinking it got more butane rich but yeah that makes sense. So 80 psi is run of mil pressure for propane?

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If there isn’t more propane just a higher ratio does that explain the increase in pressure? It’s the same amount of not less than when I filled it, right?

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I dunno personally, I never have run straight propane.

If my mix gets to around 70 psi at room temp I change my gas out, used to anyway. I’m running straight n tane now.

(mind you, I’m small time, my runs are a qp at a time at most. My tank is tiny lol)

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Word. Yeah mines only 2.5 lb cls. I upgraded from a 1/2 lb tamisium. Know all about tiny tanks lol

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I’d burp down to 50 psi. Epa limit on propane waste per day should be taken into account

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wrap your head around this graphic…

Butane/ Propane recovery rates - #6 by anon13684764 (read the rest of the thread too…)

edit: this one wouldn’t hurt either…Blending Solvents - #10 by cyclopath

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image

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by my count that is at least the 5th time we’ve stolen that graphic :wink:

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Lol I was operating under pubic domain rules lol

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what’s in your tank?

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So it’s the ratio more than the amount? That’s what’s hard for me to wrap my head around

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yep. so long as liquid and gas are at equilibrium, the pressure indicates the RATIO.

your 100lb tank will read the same pressure with 5lb or 50lb of 100% propane (or blend…but a differernt pressure)

ALL the liquid needs to become gas before that pressure will drop…

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Started with 40/40/20 then I’ve been topping off with 70/30 so I’m guessing at this point it’s mostly propane. Was chilling around 60 now it’s at 80psi

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It looks like if your tank is around 70f, 80psi would be a 70/30 propane/butane mix.

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you guys think i can recover propane with my trs 21 and just regular ice on my coil instead of dry ice?