stage regs - any preference

[Rod Abbotson]

one of the the excuses i was given was that the hp seat isnt compatible with high pressure o2, during the o2 clean does this get changed to a different one or is this fantasy?

OK this is a huge debate and has never been resolved to anyones satisfaction, its just that the reduced risk of DCS with high O2 deco outways the risk of an O2 fire in a reg. This IS possible and quite nasty when is happens, but is a rare event. (In these cases the regs where probably WAY OFF O2 clean!)

To be 02 service, something needs to be
O2 designed
O2 compatible
and
O2 clean.

OK the first one is interesting at the start of the popularity on Nitrox the industry made lots on money selling everyone funny coloursed 2nd stages for Nitrox up to 40%...

then came the 40% rule ie 0-40% O2 content is treated as air (and even whacked thru mineral oil compressors with no probs!) and the 41 to 100% as pure O2. Well there has to be a line somewhere.

Most manufactureres will not guarantee O2 designed regs for over 60% but we choose to take the risk.


Oxygen compatable material means that they burn at a higher temperature and generally last longer when exposed to high ppO2s - ultraviolet and seawater damaged actually overide this most of the time!

Oxygen clean is only a theoretical state. It means that all oparts have been tested for the absence of contaniments - fine but as soon as you touch it the things is not O2 clean anymore! It gradually becomes less clean the more use it has - industry standard is that you should have something O2 cleaned every 12 months - this may be too long in some circumstances!

I clean my deco regs everyfew weeks, also this solves any problems with o2 grease crystalizing.


get the popcorn out! shouldn't have started this!

Rod

[robertsT]

Originally Posted by Rod Abbotson

OK this is a huge debate and has never been resolved to anyones satisfaction, its just that the reduced risk of DCS with high O2 deco outways the risk of an O2 fire in a reg. This IS possible and quite nasty when is happens, but is a rare event. (In these cases the regs where probably WAY OFF O2 clean!)

To be 02 service, something needs to be
O2 designed
O2 compatible
and
O2 clean.

OK the first one is interesting at the start of the popularity on Nitrox the industry made lots on money selling everyone funny coloursed 2nd stages for Nitrox up to 40%...

then came the 40% rule ie 0-40% O2 content is treated as air (and even whacked thru mineral oil compressors with no probs!) and the 41 to 100% as pure O2. Well there has to be a line somewhere.

Most manufactureres will not guarantee O2 designed regs for over 60% but we choose to take the risk.


Oxygen compatable material means that they burn at a higher temperature and generally last longer when exposed to high ppO2s - ultraviolet and seawater damaged actually overide this most of the time!

Oxygen clean is only a theoretical state. It means that all oparts have been tested for the absence of contaniments - fine but as soon as you touch it the things is not O2 clean anymore! It gradually becomes less clean the more use it has - industry standard is that you should have something O2 cleaned every 12 months - this may be too long in some circumstances!

I clean my deco regs everyfew weeks, also this solves any problems with o2 grease crystalizing.


get the popcorn out! shouldn't have started this!

Rod

Thanks- that seems a very comprehensive answer.... I'm sure others will have diffrent opinions though!

[Woz]

The HP seat on a mk 2 is a little white disc about 5mm across and 2mm thick.

Say ooooooo about 5p. Then 2 O rings at, say 0.5p each. That's less than 10p for bits. These are industrial prices, mind, not dive industry prices.

[Jay_Benson]

Originally Posted by Woz

The HP seat on a mk 2 is a little white disc about 5mm across and 2mm thick.

Say ooooooo about 5p. Then 2 O rings at, say 0.5p each. That's less than 10p for bits. These are industrial prices, mind, not dive industry prices.

Welcome back?

I can't believe that the dive industry would add on large mark ups.

[Woz]

Originally Posted by Jay_Benson

Welcome back?

I can't believe that the dive industry would add on large mark ups.

Well as a guide your LDS takes the trade cost of kit (ex-VAT) and doubles it for retail. Unless it's a mask or fins when it's trebled.

Spares you can charge whatever you like. Put it this way- I can buy BS111 O rings (that's normal cylinder O rings to you and I) for quite a lot less than a tenner per thousand.

[sccs]

Originally Posted by Rod Abbotson

Oxygen compatable material means that they burn at a higher temperature and generally last longer when exposed to high ppO2s - ultraviolet and seawater damaged actually overide this most of the time!

not forgetting that that it also means their not combustible when exposed to pure o2

Originally Posted by Rod Abbotson

Oxygen clean is only a theoretical state. It means that all oparts have been tested for the absence of contaniments - fine but as soon as you touch it the things is not O2 clean anymore! It gradually becomes less clean the more use it has - industry standard is that you should have something O2 cleaned every 12 months - this may be too long in some circumstances!

not strictly true. o2 clean goes hand in hand with compatible really, as for one to be one thing it has to be the other to start with. for example an o-ring that's o2 compatible is not o2 clean if dipped in mineral oil. on the other hand a non o2 compatible oring that has been o2 cleaned is still not compatible

and if you look after your regs as one should do then they should not be exposed to "contaminants" there for would still be o2 clean as the only parts that are ever exposed to anything other than the supplied breathing gas are the reg casing, sealing face and the diaphragm.

so yes as soon as they are o2 cleaned they aren't, but as long as not exposed to contaminants then they are... lol