Which tanks to choose

[Cthippo]

Lighthouse Dive Center fills and services the voodoo tanks. The eddy-current is an annual along with the VIP. The added cost to maintain them adds up quick if you have multiples. I have 2 that I've since let lapse on VIP since I don't dive the AL anymore. At some point my 3 AL 80s will become dedicated 40%+ deco / O2 bottles.

So does Anacortes Diving and Supply.

That said, I think the annual is a shop policy versus a DOT one. AFAIK DOT only requires an eddy every 5 years in conjunction with your hydro. The VIP is strictly a SCUBA industry invented thing. Having the luxury of doing my own fills I feel comfortable ignoring the industry stuff where it exceeds federal law, but I recognize not everyone can do that.

 

[Dann-Oh]

I thought about HP steel, but it's going to be hard to get them filled to max pressure. LP's wouldn't be a problem filling to rated pressure. For reference, I have dove on AL80's, single and twin and surface air. Some of the company owned twins were probably steel but I can't remember that far back. Price on AL80's in the most attractive, but LP's aren't too bad.

Depends on where and how your diving. Ill use my HP100 (single back gas) if I am doing a single beach dive or if I'm diving near a fill station. I have my LP50s (for sidemount) that Ill use for beach or boat diving. I have my LP72s (sidemount) Ill use if Im doing deeper boat dives or diving with newer divers. The local boats don't really fill above 3000psi so there is not really a point to bring the HP100 on a boat dive day.

 

[Ross19966]

So back to compressors. The manufacturer sets the auto shutoff from the factory. They said to set the auto to the max pressure you will need and shut off manually for lower pressures. So should the auto shutoff be set to 3442 or higher to compensate for pressure loss after cooling?

 

[rob.mwpropane]

So back to compressors. The manufacturer sets the auto shutoff from the factory. They said to set the auto to the max pressure you will need and shut off manually for lower pressures. So should the auto shutoff be set to 3442 or higher to compensate for pressure loss after cooling?

Higher. Say 3700 or 3900 for HP. Depends on the time of year and what I'm planning on doing also.. if I don't need that high then why put the compressor through it.

You can most likely adjust that yourself.

 

[Cthippo]

So back to compressors. The manufacturer sets the auto shutoff from the factory. They said to set the auto to the max pressure you will need and shut off manually for lower pressures. So should the auto shutoff be set to 3442 or higher to compensate for pressure loss after cooling?

Are you planning on having any storage? If so, auto shutoff should be the MAWP of those tanks, which chould also be higher than the MAWP of your dive tanks. We have 6x M cylinders as storage at 6000 PSI and can fill a lot of tanks from that wothout ever starting the compressor.

 

[inquis]

If I can carry less lead, even better.

This isn't so cut & dried. Relative to an AL80, an HP120 drops 2 lb of lead/ballast, but climbing back in the boat you'll feel 5 lb heavier (not counting any difference in remaining air).

IOW, less lead is not always better.

This is partly why the HP100 is popular: drops 4 lb lead, is 1.5 lb lighter climbing the ladder (assuming the same air remaining), and holds 30% more air to start -- wins all around.

 

[Ross19966]

Higher. Say 3700 or 3900 for HP. Depends on the time of year and what I'm planning on doing also.. if I don't need that high then why put the compressor through it.

You can most likely adjust that yourself.

I'll drop them in a water bath to fill. They said the cutoff is factory set, but it they can set it I'm sure I can as well. At what PSI do these HP tanks become dangerous? I wouldn't have guessed 3900 on a tank rated to 3442.

 

[Ross19966]

Are you planning on having any storage? If so, auto shutoff should be the MAWP of those tanks, which chould also be higher than the MAWP of your dive tanks. We have 6x M cylinders as storage at 6000 PSI and can fill a lot of tanks from that wothout ever starting the compressor.

No storage. We're talking about a small compressor. One tank at a time. Looking at about 20 minutes for an AL80.

 

[rob.mwpropane]

I'll drop them in a water bath to fill. They said the cutoff is factory set, but it they can set it I'm sure I can as well. At what PSI do these HP tanks become dangerous? I wouldn't have guessed 3900 on a tank rated to 3442.

Well hydro is like 5/3's the working pressure, and the blast pressure is well above that.

For HP steels I fill to ~ 3900
For LP steels I fill to ~ 3400
For aluminum I fill to ~ 3300

 

[Ross19966]

Well hydro is like 5/3's the working pressure, and the blast pressure is well above that.

For HP steels I fill to ~ 3900
For LP steels I fill to ~ 3400
For aluminum I fill to ~ 3300

Might need to make a field trip over your way to pick your brain. You're only a couple hours away.