Filling Tanks...

[DailyLunatic]

Can anyone point me to information on filling my own tanks? I would like to know what kind of equipment is required, and how to assemble it.

I have access to air, but want to make sure I get the right types of regulators, adapters, filters, fillers, hoses, proceedures, etc.

I also want to insure that I have not missed or forgotten anything that would be unhealthy to my person. Don't want to blow anything up. ;)

Thanks,
Sterling
92.5% Pure

[rmediver2002]

You could get by with a minimalistic system having a bank or compressor output pressure gauge (depending on your source) followed by a needle valve to control flow, then another gauge to read tank pressure running down a short whip to the tank connection.

What type of air supply will you be using?

Jeff Lane

[DailyLunatic]

rmediver2002 once bubbled...
You could get by with a minimalistic system having a bank or compressor output pressure gauge (depending on your source) followed by a needle valve to control flow, then another gauge to read tank pressure running down a short whip to the tank connection.

What type of air supply will you be using?

Not sure what you mean by 'bank'

As for the air supply - Again, not sure for what you are looking.

I work for a Safety Relief Valve mfgr. Depending on what was best, I was planning to connect to either one of the test stands (npt type connection) or use its quick connect that feeds the digital gage.

I don't really know model numbers for the compressors and what. Went out just now to look and could only see the mfgr's name, Ingersol-Rand. They are Electric, not gasoline. If you need more info I could do some digging and find out.

Don't have an idea of the size of the tanks, big enough i'd guess. Judging by the size of my 30 gal aquarium at home I'd guess these to be in the 1000++ gal range. (Don't trust the calibration on these eyeballs though. Being a Draftsman for 20 some odd years makes me better at small dims, not large ones)

Stands are capable of 10,000 psi. Not that I expect to have to use that much for scuba tanks, but wanted you to know what I was working with.

Did any of this answer your questions?

Thanks,
Sterling
92.5% Pure

[DA Aquamaster]

Air is normally highly filtered in a dedicated scuba air compressor. There is normally some filtering done intiially as well as filtering to remove any oil that may have moved through the sytem with the air and a water trap is normally incorporated as well.

The type of oil used in the compressor is important as you need to ensure it is not toxic. Air used for nitrox needs to use a compressor lubricant that is O2 freindly. The filters on a quality air system are complex and expensive. But you never know, the air quality may be acceptable without adding anything. In either case I would have the air tested for quality to ensure it meets the appropriate standards.

All you really need at a minimum is a fill whip with an inline gauge
to register the pressure of the tank you are filling. This should include a shot off valve upstream of the gauge and a bleeder valve to release pressure when the tank is full to allow you to disconnect things.

Depending on the air presure in the system, you may require a reducing valve to limit pressure to your fill whip to something sane like 4500 PSI.

A cascade system would involve 2 or more large capacity tanks (normally with a 4400 psi service pressure) that are used to fill tanks. You start with one tank and fill tanks until the pressure is too low then close it and use the next one to top off the tank. You can do this in series of 2 to normally 8 tanks although more are possible. The lowest pressure tank is then used to transfill the next near empty tank, which is filled to higher presures by succeeding tanks. When none of the tanks in the cascade system have enough pressure to fill your tank to it's full service pressure, you need to refill the system.

The advantage is the cascade sytem can be filled periodically from a relatively simple non-automatic and perhaps rather low capacity compressor and quickly fill a number of scuba tanks in between compressor runs. With proper saftey precautions the system can be trailer mounted and be portable, allowing it to be trailered to the dive site. The downside is that the tanks in the airbank can run $400-$600 a piece and a lot of plumbing and valves are required and it can get spendy.

Most dive shop compressors use an airbank with several high volume tanks to limit the number of times the compressor has to be run. Many are also automatic where the compressor will turn it self on at a set pressure and then thurn it self off when the airbank is full.

[Scuba_Vixen]

Global Mfg. Corp. is a great source of info and equipment. They have a great tech dept. as well, and you can learn much from their online catalog (pdf format one is best) and their library. Good luck.


Darlene

[Snowbear]

... have some sort of CO2 filters and CO andmonitors also. You say the compressors are electric, but even a small amount of CO can get really toxic at increased partial pressures. Our compressors at work have automatic shut-down switches if any CO is detected. We aren't allowed to re-start them until an air sample is sent in and tested for purity. Obviously you don't want much moisture either, as this can corrode your tanks - here are filters for this also.

[rmediver2002]

DailyLunatic,

Check the compressor, it may have a filtration system in place already. Could you speak with someone who conducts the maintenance on the unit?

questions for them:

Grade of air produced?

Filtrations system in place?

Air testing ever conducted?

if there is already a filtration system (good chance if used for a calibrated test station) then it is not going to take to much to set something up. If it does not then adding in filtration (around $1400 for a new 12,000 cubic foot system) is most likely going to make it to expensive...

Let me know what you find out?

Jeff

[canuckdiver]

does anybody have some names of manufacturers for the high-pressure filter stacks?

[DailyLunatic]

Scuba_Vixen once bubbled...
Global Mfg. Corp. is a great source of info and equipment. They have a great tech dept. as well, and you can learn much from their online catalog (pdf format one is best) and their library. Good luck.

None of their library links were working. Thanks for the lead though.

Sterling
92.5% Pure

[rmediver2002]

Here is a few suppliers you can check out...



http://www.eaglecompressors.com/air%20purification.htm

http://www.bauercomp.com/miami/breathingair/scubadiving.htm
(scroll to bottom of page)

http://www.aplusmarine.com/catalog_pdf/2002PAGES59-72.pdf


(might be better to just purchase a replacement canister from someone and set it up yourself for a smaller unit...)

Jeff Lane

[DailyLunatic]

rmediver2002 once bubbled...
DailyLunatic,

Check the compressor, it may have a filtration system in place already. Could you speak with someone who conducts the maintenance on the unit?

questions for them:

Grade of air produced?

Filtrations system in place?

Air testing ever conducted?

if there is already a filtration system (good chance if used for a calibrated test station) then it is not going to take to much to set something up. If it does not then adding in filtration (around $1400 for a new 12,000 cubic foot system) is most likely going to make it to expensive...

Let me know what you find out?

Jeff

Asked some of the people using the equipment as well as the Foreman:

First, they said maintainace is performed when the compressor breaks. (most likely a joke, but I would not count on it being done more than once a year or so at best)

Grade of air was an unknown concept.

Filtration system was a water trap and a check valve.

No air testing has ever been done to their knowledge.

*****

$1400 for a filter?!? Surely not. I've seen portable scuba systems advertised for $2900. That would make half the cost of the system in the filter alone. ;-0

What is it about the filter that makes it so expensive?

Sterling
92.5% Pure

[rmediver2002]

Well they really are not that expensive (components) but most of the systems are designed to have a minimum cartridge life of 12,000 cubic feet. The housing is the most expensive component usually made from stainless steel and designed to ASME standards (basically the working pressure is around five times the compressor working pressure at a minimum) They rarely recieve more than a visual inspection (if that at most installations...)

The replacement cartridge if bought pre-assembled for less than $100, or you could purchase the chemicals and re-pack the cartridge yourself. I have 3 larger units and two portable units and prefer to just purchase the redi-made cartridges...

Are you perhaps using some type of booster to produce the 10,000 psi or is the compressor output rated 10,000 psi?

You could call around and find a decent price on a filter housing, figure around $100 for a three part filter (activated charcoal to remove smell, desicant to remove moisture, and a catalyst to convert small amounts of CO to CO2), then the associated gauges and filling yoke we discussed.

You will need the capability to pressurize the filter tower before begining filling of the cylinder as the cartridge will not be efficient at lower pressure or if humidity levels are to high.

All this will set you up for air filling of cylinders, you will need to add in some additional filtration for any gas blending...

I would make sure you test the air before filling any tanks, this is not something to risk getting hurt over...

Jeff Lane

[DailyLunatic]

rmediver2002 once bubbled...

<snip>
Are you perhaps using some type of booster to produce the 10,000 psi or is the compressor output rated 10,000 psi?

<snip>

I would make sure you test the air before filling any tanks, this is not something to risk getting hurt over...

Jeff Lane

Yes, the outside unit brings the pressure up to around 5,000 psi, then the inside booster from there. Missed that when I was poking around outside yesterday, sorry. I can tap into the system at another stand that is not serviced by the booster if pressures above 5,000 are a prob.

I fully agree with the sugestion of testing. 'If' I proceed with this I will have the air tested. I had apparently wrongly assumed that as the compressors were elec that CO would not be a prob, and had not considered toxic oils at all.

http://www.plans-kits.com/kits/scubakit.doc

Additionally, I had assumed that filtration would be simpler and less costly. In digging today for more info I came across the above link. What are your opinions of this Scuba Kit listed for $350.00? It is more in line with what I had imagined I was getting myself into. I realize it would not be appropreate for a DS, but would it serve a single user?

Sterling
92.5% Pure

[rmediver2002]

Looks like a great little kit, everything you will need except a needle valve to control the flow from the station.

Your going to be able to use the boosted air supply, just make sure your keeping a good eye on things so you do not exceed the working pressure of the system.

You could add in a relief valve on the system to ensure you do not overpressurize it... (you most likely have access to plenty there right?)

Good price in my opinion, try to find out the rating on that filter (should be rated in cubic feet) and determine how long it will last you. I would just plan to replace it every year anyway but if your doing many fills you might burn through it quicker...

The biggest factor in consuming them is moisture...

Thank you for that link, let me know how it goes!!

Jeff Lane