Short-filled AL100s

[2airishuman]

I've recently been on two trips with reputable operators where I requested a 100 cf cylinder in advance of the dive. Both operators used AL100s and filled them to 2900-3000 PSI rather than the 3300 PSI for which they are rated, so I had around 90 cf of gas rather than the 100 cf I had expected.

Also ran into this once a year ago and got the operator to top off the cylinder. These last two experiences involved charters where there wasn't a compressor at the dock so no practical way to do that.

One more question to ask when choosing operators, I guess. How widespread is this?

 

[scubadada]

Do you think all the operators/fillers know that AL100s are filled to 3300 rather than 3000 psi? Maybe they're just used to filling 80s?

In SE FL, I rent AL80s and generally have "good" fills. I went back and looked at my last 20 cylinders from Boynton Beach, West Palm, and Jupiter. The average fill was 3278 psi (2966-3492). I'm not sure I've ever seen a rental AL100 here, most operators will get you a steel 100 is you ask, and pay for it. The few times I've gotten steel 100s, the fills were up to spec.

 

[Wookie]

Here is my 2 cents. Regardless of where you go on vacation in the world, with the possible exception of cave country in Florida, you are going to get a 3000 PSI fill. The ubiquitous aluminum 80 is so ingrained in the psyche of dive operators for numerous reasons, that a 3000 PSI fill is all you will get. They hot fill to 3300 and let it cool. So, whether you are diving a LP steel, a al-80, or a 4500PSI composite cylinder, it's going to have 3,000 PSI in it. Might as well dive the LP95 with 3,000 as a HP cylinder with 3,000 PSI....

 

[Aqua-Andy]

300 psi is not a lot to drop when a tank cools down. Always try to give the shop enough time to properly fill the tank and check the pressure before you leave the dive shop. When filling a tank it heats up, there is just no way around that and most shops do not like filling above the rated pressure regardless of temperature. I believe the tank ratings are at 70F so you can overfill a tank if it is warmer but good luck explaining that to most dive shops.

 

[IBjones]

My LDS has a 3x3 foot concrete pool they put the tanks in to fill them so I always get a good fill.

 

[Wookie]

Oh, good. Another wet fill discussion.

 

[RainPilot]

Let's hope not Frank. For the love of all that's good...let the Wookie win.

It's important to remember the OP was referring to a fill provided by a dive operator. There's a country mile difference between an LDS filling your tank for you, where you can supervise/remind them what it is that you want exactly, and a compressor jockey filling 200 tanks in a row for the weeks diving with the compressor set to 3300 and brain in neutral.

 

[BoltSnap]

Oh, good. Another wet fill discussion.

Well, we haven't seen it for a while, we need a change from the BP/W vs. Jacket BC discussion for fun I think

 

[Ghetto Diver]

Nitrox?
Some won't fill them past 3k

 

[teknitroxdiver]

Nitrox?
Some won't fill am last 3k

Only the ignorant.