Q on SCUBA K/DIN/Adapters

[Oz]

I'm thinking positive thoughts about soon upgrading to a PCP pistol. To get started I have purchased a SCUBA tank with the traditional U.S. K valve. I understand that the PCP pistols come with a DIN-based adapter so I bought a K->DIN adapter valve for $21.

Questions are:
1) Do the adapters that come with PCP pistols have some type of rubber grommet on the bottom face so that when screwed in, it seals? If you see the K->DIN adapter I bought, it appears that it's designed for that type of seal. I just want to make sure the K->DIN I have is correct for the PCP adapter that comes with PCP pistols.


2) Because I love information and statistics, I really want a gauge on my SCUBA tank. I have a 5000 PSI gauge which has a 1/4" male NPT fitting. The most basic success would be a DIN-> 1/4" female NPT fitting. It would require swapping the pistol filling adapter with the DIN->1/4" female NPT fitting and gauge, which isn't great, so...


3) The ideal situation would be a DIN 'T' fitting which would have male DIN to screw into the K->DIN value, then a male DIN-> 1/4" female NPT fitting on one side for the gauge and female DIN on the other side for the male DIN->PCP pistol adapter.

I have the feeling that I might be trying to reinvent the wheel. Anyone have any thoughts?

[bruce]

In answer to question 1. Yes they do have a grommet that seals against the bottom face of the fitting.

[edster99]

As far as I am aware there is no adapter for sale that does what you want - I have certainly never seen one like that. You could get one like http://www.golemgear.com/p-323-lola-uni ... valve.aspx that you could put a check valve in one outlet and the adapter in the other. You can get cylinders with DIN valves with built in pressure gauges, - see http://www.best-pcpfittings-quickcoupli ... inders.asp but I cant seem to find the valve alone. Good luck!

[Fred Mannis]

Air Guns of Arizona has what you are looking for. Go to their sections on Adapters - Air and Fill.

Here is a similar system from Straight Shooters: http://www.straightshooters.com/pcpitem ... 70p40.html

I have tried the Foster Quick connects and don't like them. Tend to leak.

I don't understand why you want a gauge on the scuba tank. You know how much pressure is in the tank by looking at the gauge on the cylinder you just filled. KISS

[edster99]

If you get a proper fill you could have either 232 or 300bar (3500 or 4500 psi) in your main cylinder. If your AP cylinder is only rated to 200, you would want to know before you open the valve what the incoming pressure is. Then you can do it very carefully, if you need to stop before you get all the way to equilibrium between the cylinders. Repeatedly filling over working pressure on the AP cylinder is not good for it, and a waste of gas as you then need to bleed it down before you use it. After all, you wouldn't want to overpressure the very expensive AP internals...

[Steve Swartz]

If you tell the dive shop the tank is for a PCP gun or paintball gun, yoiu will be lucky if they give you 3000 psi.



Even though my Morini cylinders were originally rated for 250 bar (the old users manual) the same exact tanks are now rated for 200 bar (the new manual).

So, using one of Scott Pilkington's in-line gages, I fill the cylinders to 300 psi. Three of my cylinders have excellent gages; the 3000 psi fill take them to the top of hte green. On my fourth cylinder, the 3000 psi fill takes it well into the yellow.

1. Don't trust the cylinder gages
2. Scott sells an excellent yoke adapter with a good gage
3. Dive shops will underfill your tank if they know it's for anything other than SCUBA
4. Tank fills are cheap even if you are getting underfilled . . .

Darn that stupid gas law!

[Steve Swartz]

" . . . I fill the cylinders to 3000 psi . . . "

sorry

[edster99]

Different rules in different places - here if you ask for a fill you get one, the end use is not the issue.

[jak10x1]

Where did you get the liquid filled 5000 PSI gage?

Thanks, John

[Oz]

Where did you get the liquid filled 5000 PSI gage

Harbor Freight, believe it or not.