Scubapro 02 100%

[aquanaut69]

Hello all

I need some advice.....

I am just about ready, equipment wise to take my TDI Advanced Nitrox & Deco procedures course. The last piece of equipment is the pony bottle regulator itself!

I have a Scubapro R390 (my old octopus, not yet O2 cleaned) and would like to use this with a Scubapro 100% O2 compatible Din first stage.

Can anybody answer if Scubapro do a 100% 02 1st stage? Or do I have to purchase a normal Scubapro 1st stage and then get it converted for 100% 02 use?

Or do I buy an Apeks 100% 02 compatible out of the box?

Any advice much appreciated!

PS. Why does a nitrox cleaned up to 40% 1st/2nd stage need to be additionally cleaned for use with 100% O2?

Thanks in advance!

[Woz]

It's all bollocks, O2 cleaning. All Apeks regs use EPDM seals and are O2 clean from the factory and use O2 lube, too.

Scubapro mk2 1st stage is fine for 100% O2 mainly as it has 2 O rings and an HP seat as the only elastomers in it. Change the 2 O rings for EPDM, O2 clean, replace the HP seat for a new one and you're off. 2nd stage just as easy to clean but works at lower pressures so not as critical.

[scubacoach]

At present the MK20/25 is the only reg that has a seat suitable for a mix higher than 40%. All the rest of the Scubapro range are suitable out of the box to 40% ( The 40% is due to NOAA, and is in the end a misnomer, as any mix above 21% should be treated as an oxidiser). At a recent seminar MK2 for 100 O2 was mooted to be available soon ( under certification with Test house). If you use any other scubapro First stage reg with a mix higher than 40 % and you have a failure then it is down to you.
Second stages are a different matter as they are medium pressure they are not so critical. Just remember to open those valves slowly, gas can reach the speed of sound in the hose between first and second stage.

[Woz]

How strange. The only components in a mk2 1st stage are 2 O rings and an HP seat. Change them for something compatible, clean it and that's it. It's about as complex as a brick.

[Finless]

FWIW I have attached my Scubapro 360 and 500 regs + a really cheap Apeks reg to my 100% in the past. They were all 'O2 prepared or cleaned' during their last service.

Whatever, I have used them briefly (they are all backups on the diff cylinders to my FFM/gas switch set up) with 100% O2 - although I usually now use 80%

I have to admit they have only been breathed as a surface test as I have never need to bail out of my FFM since I got the TDI O2/Deco ticket.

Look on the bright side - you'll probably be on TV if something does go wrong!!

[Steven]

Originally Posted by Woz

How strange. The only components in a mk2 1st stage are 2 O rings and an HP seat. Change them for something compatible, clean it and that's it. It's about as complex as a brick.

what even stanger from your description is that when I took my mk2 scubapro 1st stage in to be serviced and o2 cleaned, I was told it cannot be o2 cleaned!!
why would that be?

[scubacoach]

It is because the current hp seat is not compatible with high percentage O2. As simple as that. The factory do have seats that are suitable but are awaiting approval from test to be allowed to supply.

[Woz]

Blimey. They must make their seats out of grease then cos it looks like nylon or HDPE from where I'm sat. Maybe UHMWPE at a stretch. None of which go pop with O2.

[fatone]

As Scubacoach will have seen at the Scubapro seminar, Scubapro have some excelent photos of Mk2's that were put to a 100% oxygen trial by a US laboratory test house that have done just that, exploded !
Scubapro have got a Mk2 in the wings that is being tested in Germany for O2 use.
I dont know why Scubapro dont use the existing Mk2 components if as Woz says they are ok, but they, Scubapro, probably have a good reason.

[Woz]

I'm sure you can make anything go pop if it's greasy enough- say if you took an old reg, whacked it on an O2 cyl and opened the valve as fast as you physically could. But the piston has 2 O rings on it, a big one and a little one, which can both be O2 compatible and an HP seat, again which can easily be made O2 compatible.

Unless I'm missing something obvious like they make the 1st stage body out of titanium or something.