How to get a good fill

[Gill Envy]

I'm glad to see this issue being brought up and I hope shops are paying attention. Whether or not one considers a few hundred PSI considerable, I think the cold rated pressure should be a reasonable expectation once the tank is cool. From a business point of view, it seems like a no brainer to me, good fills are a sure way to make customers happy and I don't understand why so many shops skimp on that last little bit of boost, my guess is that they don't truly get just how good a good fill feels to a diver.

Hands down the best fills I have ever gotten were at Bamboo Reef in Monteray CA. They had "free Air Fridays" back in the mid 90's and the only way they could keep up with the deluge of divers on Fridays was to have a refrigerated water tank. It was fun to be the first customer in the morning and have them crack the thin layer of ice in the chiller with your tank. Within 10 minutes your tanks were full to rated pressure and cool, every time!

Follow the advice in this thread and spell out your expectations to whomever is filling your tank and get your gauges checked.
george

[dscuba]

Ok, it was answered off this thread, primarily a lack of understanding on my part.

The issue is yoke can only handle 3000psi (3000 or 3300 I'm still not sure). My [yoke] first stage does indeed say "3000 psi" on it. Looks like DIN is the way to get the full capacity out of my HP120 tanks.

[CaptnJack]

Ok, it was answered off this thread, primarily a lack of understanding on my part.

The issue is yoke can only handle 3000psi (3000 or 3300 I'm still not sure). My [yoke] first stage does indeed say "3000 psi" on it. Looks like DIN is the way to get the full capacity out of my HP120 tanks.

Yes, some yoke regs are stamped 3000psi. But that is not a limitation of every yoke (some are stamped with obscene 4500psi ratings). I don't use yoke, but if I had one on hand I wouldn't quibble about putting it on a tank with 3300 in it.

By the same token, my compressor hoses are rated 3000psi, but I fill to 3800 hot sometimes (the tanks cool to 3500). The hoses have a speced 4x safety factor, 12,000psi burst rating so I don't really worry about 10mins at 3800.

[nwbobber]

So why not pull the plugs out of your valves when bringing them in for fills? Then they can be filled to the rated pressure. Also a DIN conversion was in the neighborhood of 75 bucks for my scubapro reg, and a much better more secure setup. Well worth it IMO.

[ArcticDiver]

Though not mentioned, getting a good fill is also a problem at some boat operators. A couple I've run into when I travel routinely short their fills as much as 500psi. At first I accepted their excuse that maybe it was heat, or my gauge wasn't right, etc. But, after I had my gauge calibrated and I got a bit more observant about their operations I came up with the real reason. Short fills mean short dives. Short dives mean short trips and less time and expense. The goal apparently is to get people's money and then minimize expense to maximize profit.

However, to their credit, almost all when asked to top up the cylinders will do so. Some can't as their fill facilities aren't co-located with the boat.

Some of these operators also routinely run the granny line from the stern to the mooring bouy with over a 100' of slack. I've seen more than one situation where with the current and slack line by the time a diver got from the stern to the bow they had used so much air their dive was short indeed.

Pretty shortsighted in my opinion. But, my opinion doesn't count.

[no excuses]

Good advice. I solved the problem by just buying big tanks. For rec. diving it's pretty hard to exhaust NDLs/thermal comfort on a 119 or 130 even if there filled a little short. I like to walk into the shops and get them filled on the spot for the most part, so this works well for me. A 130 shortfilled to 3100psi is still 117 cu ft

It just beats the hassle of being nitpicky about it. Of course in a perfect world all fills would be at or slightly over rated fill pressure.

Thats why I picked up a pair of 130's also, oops only 3200 psi damn thats only 120 cu ft . I get cold and am ready to get out of the water before I am out of air.

[no excuses]

oops double post

[Mattleycrue76]

Though not mentioned, getting a good fill is also a problem at some boat operators. A couple I've run into when I travel routinely short their fills as much as 500psi. At first I accepted their excuse that maybe it was heat, or my gauge wasn't right, etc. But, after I had my gauge calibrated and I got a bit more observant about their operations I came up with the real reason. Short fills mean short dives. Short dives mean short trips and less time and expense. The goal apparently is to get people's money and then minimize expense to maximize profit.

However, to their credit, almost all when asked to top up the cylinders will do so. Some can't as their fill facilities aren't co-located with the boat.

Some of these operators also routinely run the granny line from the stern to the mooring bouy with over a 100' of slack. I've seen more than one situation where with the current and slack line by the time a diver got from the stern to the bow they had used so much air their dive was short indeed.

Pretty shortsighted in my opinion. But, my opinion doesn't count.

Althought I have heard of this type of business model on carribean cattle boats or with cruise ship operators that doesn't seem to happen around here. Most of the boats have you bringing your own tanks and no one ever accused the Mark V crew of being greedy and profit driven. Those guys would bend over backwards to make sure everything was right. Virtually all of the other dive ops in the Sound have great reputations as well. Guess we're lucky here.

[ArcticDiver]

Though not mentioned, getting a good fill is also a problem at some boat operators. A couple I've run into when I travel routinely short their fills as much as 500psi. At first I accepted their excuse that maybe it was heat, or my gauge wasn't right, etc. But, after I had my gauge calibrated and I got a bit more observant about their operations I came up with the real reason. Short fills mean short dives. Short dives mean short trips and less time and expense. The goal apparently is to get people's money and then minimize expense to maximize profit.

However, to their credit, almost all when asked to top up the cylinders will do so. Some can't as their fill facilities aren't co-located with the boat.

Some of these operators also routinely run the granny line from the stern to the mooring bouy with over a 100' of slack. I've seen more than one situation where with the current and slack line by the time a diver got from the stern to the bow they had used so much air their dive was short indeed.

Pretty shortsighted in my opinion. But, my opinion doesn't count.

Althought I have heard of this type of business model on carribean cattle boats or with cruise ship operators that doesn't seem to happen around here. Most of the boats have you bringing your own tanks and no one ever accused the Mark V crew of being greedy and profit driven. Those guys would bend over backwards to make sure everything was right. Virtually all of the other dive ops in the Sound have great reputations as well. Guess we're lucky here.

All the instances I've seen of this have been in FL. The others I've heard of have all been in the Carribean or MX.

Yes, you are lucky to have your economic, social and dive lives all converge at the same location.

[Tom Nic]

Late to this party, but my .02 psi...

How to get a nice fill:

1. Ask nicely.

2. Be specific. My requirements for percentage or the need for a monster fill will vary from week to week. If I communicate clearly ahead of the time I get very well taken care of.

3. Give them adequate time.

4. Measure the pressure in your tanks yourself before you take them home. Don't take anyone's word for it unless you're willing to live with the results.

If you dive Nitrox you're analyzing them anyway, pretty simple to slap a gauge on them.

[gcbryan]

There's a lot of reasons for shorter fills on HP tanks. Less so with LP tanks.

Some shops/boats can't handle HP pressures as well as others.
Some newer divers are concerned with overfilling (they've heard that it's wrong or dangerous).
Some shops feel that way.

It's much harder to get that last 500 psi in there with a 3500 psi tank. If you can give it a slow fill, let it sit overnight and then give it a slow top off with a slight overfill to account for cooling that's the best bet.

If you want to wait for the fill it's much harder to do because of heat buildup. Even if you fill relatively slow it's almost impossible to get that last 500 psi in there without excessive heat being generated without an over night waiting period.

As mentioned there are differences between shop gauges, your gauge, getting in the water will drop the reading especially if it was the least bit warm when you last read your gauge.

I agree that the best thing to do is to have a relationship with a particular shop, let them know you can leave them overnight and can wait for a slow top off the next day including hopefully a slight (or more) overfill.

If you never overfill beyond 4,000 psi it's hard to get in the water and have any more than 3500 psi no matter what you do in the practical realm.

If it's a big dive where you actually need it full then that's where I'd go to the most effort. Otherwise, a consistent 3300 psi (when cool) doesn't bother me on most days.

Some days if you want the tank filled while you wait they may not even have higher pressure air banked in the 3000-3500 range and may have to turn on the compressor for this. If it seems like you are more in a hurry than worried about a 3500 psi fill they may give you something less. Polite communication works well. No one is trying to cheat anyone.

It's generally not worth the hassle to me to make two trips. I can wait around in many cases and I don't mind overfilling while hot. I generally have been lucky enough to fill my own so I know it's hard to do within an hour.