Bad luck with fill’s

[TuckerM80]

Forget the valves. The correct working pressure is on the shoulder of the tank. I used to fill my working pressure with a bit of paint so it stood out. Now I fill my own and cut out the tank monkeys.

I see you are from cave country Mr. Chairman. That is where I do all of my diving. Maybe we could get out for a dive, and I could convince you to share some non-monkey’d nitrox

 

[The Chairman]

I see you are from cave country Mr. Chairman. That is where I do all of my diving. Maybe we could get out for a dive, and I could convince you to share some non-monkey’d nitrox

It's not running at the moment as I am healing. It will be though, and me too.

 

[rhwestfall]

If he was partial pressure filling, then he did a decent job anyway.

I respectfully disagree. All we do up here is PP blends, and they damn sure better be closer than 1% (typically +/- 0.2%). You got 24% on a 32% request? No bueno!

EDIT - Reread... 30/31 on a 32 isn't too bad, but we still typically get better... IMHO, +/- 0.5% should be the outcome. At least they were "low" vs. "hot".

 

[rx7diver]

... If it’s truly 3500 and not 3442, then you have 7/8” neck and 300 bar DIN valves, that’s a huge clue, those are kind of hard to miss, that’d be one tank I’d fill without needing to look for the service pressure stamp. ...

Forget the valves. The correct working pressure is on the shoulder of the tank. I used to fill my working pressure with a bit of paint so it stood out. Now I fill my own and cut out the tank monkeys.

Yes, the valves can be misleading if you don't look carefully! I own one of those slanted-back 300 Br-looking valves that are, indeed, for max 300 Br fills (same number of threads), though made to fit a "normal", 3/4" 14 NPSM scuba cylinder. Looks almost exactly like the valves that came originally on my Sherwood Genesis (3,500 psig PST) HP100/120's, except for the (larger) NPSM thread, the different burst disc assembly ("4000-120 3300" vs. "4000-120 3500"), and the different service pressure stickers ("Service Pressure 3300" vs "Service Pressure 3500"). Purchased it new ca. 1995 when I purchased my HP100's. Purchased it to use on my first deco cylinder, an OMS (Faber) 2,640 psig LP46, which we filled with EAN32/36 pumped north of 3,000 psig.

As noted above, it's always best to read a cylinder's fill pressure off of the stampings on the cylinder's shoulder.

rx7diver

 

[greeniguana]

Plural possessive noun's.

 

[rhwestfall]

I have a Farber (ScubaPro) steel from the 90's that has 3000 psi service pressure stamped on it...

Get some "interesting" fills with it.

 

[happy-diver]

and what about the ten other customers that went through whilst everyone was being so polite

 

[Belzelbub]

Just left a scuba shop where I paid $52 for four nitrox fills on my steel HP 120’s. Diving thirds, all tanks had at least 2000 psi in each. Asked for 32% nitrox and my analyzer comes up with 30% on two and 31% on the other two.

Getting 30% or 31% after requesting 32% is not a big deal. Will have little impact.

Service pressure stated on the tanks is 3500 psi with dedicated DIN valves. Tanks are were “filled” to 3100 psi.

This, on the other hand is an issue.

I am a cave diver but I dive HP cylinders so I don’t have the issue of not being able to get “cave fills”. At first I was questioned how I know they are HP 120’s. Employee pointed to an hp120 with a tank boot on, and mine are removed. Held my tank up to the shops tank and explained I have the boots removed and they look smaller.

Don’t your tanks have the service pressure and test pressure marked on them? That would have been a more definitive check. Size would indicate capacity more than pressure.

I had those same tanks filled at another location and they were marked 32%, but when I analyzed them myself with my personal analyzer, and then a buddies analyzer they came out at 24%.

Yeah, that’s definitely a bigger issue. Did you check the mix when picking them up? I absolutely would have had them try again if I asked for 32 and got 24.

Has anyone else dealt with poor fills ? Should I have spoken up at my dive shop visit today ?

You absolutely should have spoken up. Could be an honest mistake on the low pressure. Politely educating them doesn’t hurt. After all, you payed for a fill. You got less than that.

Shop closest to me filled a buddy’s HP100s to 3000 psi. I never use that shop. My preferred shop is a bit further away. In fact, there are probably 4 or 5 dive shops that are closer. I go there because they treat me right. Only once did I have an issue with a fill. Turned out to not be their fault. They filled it, full, but the valve was leaking slightly. By the time I went to pick it up, it was down to around 3200. They topped off initially, but also sprayed it and found the leak. They took care of the valve and refilled for me with no problems.