Get a LP85, white paint helps, they are often mistaken for aluminum 80’s and they will get pumped to 3k, you’ll end up a lot closer to 100cf than a short filled HP tank.
Question regarding tank fills
- Thread starter CaptainPanda
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Catito
Contributor
Yes, that was interesting to me that we are getting similar results with different fill times.I'm surprised that you get that much pressure drop. 3 hrs is a long time. It takes me 20-25 min to fill an empty 3500 with my compressor. I take it to 4K and it usually ends up around 3600 when cooled (still learning though). The tanks (even filling 2 sets of doubles) are noticeably warm. Not hot, but pretty warm.
Before the compressor I told the LDS multiple times they were shorting me.... he said it must be my gaugeI checked with another and read the same thing. @ $12 / fill you'd think they'd make darn sure it was topped up. 3500 would usually be 3100, but they would hot fill to 3500 and that's it.... not a psi more. I disliked that shop anyway.
The Force E fill shop in Pompano Beach also uses a water bath, but I have no idea what that does for HP tanks because I only fill my LP tanks there. (I don't take my HP tanks to Florida when I go.) I always get more gas than advertised, so I don't worry about the LP fills there.
In contrast, I used to use a shop in Pompano Beach that had most of its employees refuse to fill my LP tanks to their rated pressure. They said it was too dangerous. They would hot fill it to about their rated pressure and then let them cool to something less. Ironically, they filled AL tanks with a rated pressure of 3,000 PSI to about 3,300 PSI, evidently feeling that the overfilling made their customers happy. When I dived with them with friends who rented their tanks, I would have the least gas of the group when I was diving with LP 85s and they were diving with AL 80s.
One of the guys who filled their tanks was a cave diver, and when he filled my tanks, it was a different story.
The cold water bath helps immensely with filling HP tanks quickly. I use them regularly for HP fills
Catito
Contributor
I’ve seen that. Leads to overfilling. I say good! I knew there was a reason I liked it
Speaking from experience it probably does. I typically have 3600-3750 once the tank equalizes with the air temp. That’s perfectly fine to me.
If my AL tanks are overfilled I will bleed them down to 3100 or so if I’m not using them right away. My HP steel tanks I have no issue leaving them with 3600-3800.
Rusty Shackleford
Contributor
My only issue with a water bath is if they don’t purge the whip and the valve before they couple it, they will blow water into steel tanks.
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