SCBA unmodified valve adaptor help

[ghengis]

Hello all. New here and tried searching through the forum with no luck. I currently inherited an 80cu ft. scuba tank from a family member and just recently bought a perfect condition scba 3L bottle with an unmodified valve that looks like

 . I was wondering, where do I get an adaptor (what kind) so that my scba tank can be converted to the similar nipple that's on my paintball carbon fiber bottle? I'm assuming I could do this so that my scuba tank can fill the scba bottle??

Reason in doing this is because the scba has expired (15 years). My scuba tank however I can fill it anytime I want for $5. Please let me know if this is possible at all? 

Thank you. 

 

[dizzums]

umm .. filling from a scuba will limit the capacity quite a bit .. looks like you need a cga347 fill adapter .. you can find them on ebay for 50 or so bucks ..

 

[ghengis]

So what options do I have now to fill this scba 3L bottle? I see some using Yong Heng? Any guides on purchasing the right adaptor, tools etc? Any guidance is appreciated. 

Thank you all. 

 

[steve-l]

You are going to have to do a lot better in describing what you have to get meaningful help. American bottles use different threads for their bottles. They are labeled Gas threads, but they are relabeled NPS (National Pipe Straight) threads. Some European bottles use BSPP ( British Standard Pipe Parallel) gas threads, but most use Metric threads, Steel bottles usually use M25 x 2.0 mm and most Carbon/ aluminum use M18 x 1.5 mm. Most SCBA bottles world-wide have adopted the M18 x 1.5 mm standard. However, that is not the end of the dilemma. Outside of the bottle valves and adaptors, most threads for high pressure gas fittings use BSPP, but some threads used for whips and gauges are NPT (National Pipe Tapered). Even worse, the standard quick connect fittings in use, often called Foster fittings, are NOT industry standard.

This is a real potential safety issue. We are dealing very dangerous pressures here and a mismatch is down right dangerous! For instance, the British standard thread form is 55 degrees and the American and Metric thread form is 60 degrees. Metric threads are stated by diameter and pitch (distance traveled per revolution). American and British threads are measured by the number of threads in one Imperial inch or TPI. British and American standard threads often use the same TPI count, which means they appear to almost interchange with some resistance. Do not mix up the two! One more tip, NPS and BSPP threads seal with seal washers either at the base or at the top of the fitting. All Tapered threads NPT or BSPT seal on the thread with a teflon tape, packing cord or a sealing compound. Do not mix this up either, it is dangerous!

 

[Gerry52]

The SCBA valve your picture shows requires a CGA347 fill adapter (which you can find on Ebay. Get "hand tight" version) as Dizzums said. Don't know what your paintball tank connection looks like as there no picture. Your SCUBA tank cannot "fill" the SCBA bottle as a high pressure Scuba is around 3200psi, the SCBA is 4500psi.

 

[runner57us]

Others have mentioned the max pressure difference already. Adapters are available or can easily be cobbled together but you first need to know what valve you have on the scuba tank. The two most common are a K valve and DIN valve. Once you confirm which you have then you just need the parts to go from CGA347 to DIN or K. One way would be to buy one of the SCBA Fill whips that already has a CGA347, gauge, purge, hose, and female foster and then hook the DIN/K with a male foster.

 

[ghengis]

Thanks everyone. I ended up contacting Air Tanks Plus to get an idea what I needed for my Scott SCBA 30 minute tank. Finally received my order for the CGA-347 SCBA adapter and it works as intended.

Works great and is a one way valve so don't have to worry about loosing air with the SCBA tank when I shut down my Yong Heng compressor. I ended up leaving my Scuba Tank alone for filling my paintball carbon fiber tanks. I messed around with the Scuba tank to fill the SCBA tank and it litterally dropped from 3100psi down to 1500psi ... LOL .. 

After getting my Yong Heng compressor, I don't think I need to visit the diving shop any longer lol.