Converting regs to be O2 clean

[Twinsetmad]

Originally Posted by jonesor

So, if I've had them from new, I would be fine to 50% and I should just replace the O-rings with viton ones?
That's good!

No... you've missed it. They will be fine for 50%... you don't need to do anything... use them, they will be fine. Don't touch the Orings.. use them as they are.....

[scubacoach]

The problem can be cross contamination to your cylinders which will be filled using 100% O2 If you have silicone on your valve threads and this gets into the hoses of the filling bank some time there after a fire may occur. It might not happen to you but some one later may have their kit go up in smoke or the gas monkey gets burnt. That is as a worst case. Which is I believe what happened at NDAC a couple of years ago when someone was checking the )2 content of their cylinders prior to a training dive.

[Twinsetmad]

So... here we go, the same old cherry, about O2 cleaning and scare mungering. How can anyone guarentee that something is O2 clean... you can't..... from the moment it leaves the shop it COULD be contaminated.

A good example is a car MOT... it only guarentees your car is road worthy the day its been MOTed....the moment you drive it out.... no guarentee.

its all therefore's and what if's....

if your using nitrox to 50% then you'll be fine with your regs as they are.

[scuba g]

Originally Posted by Tubs

This is definatly not true, if ther reg was serviced in the past using silcone grease then it is a possable ignition point for the o2.
O2 clean means nothing inside the reg has flamable grease that could cause a o2 flash or fire. When o2 regs are cleaned only a o2 compatable grease is ever used (if done by a profesional and not someone in their shed)

I meant as in the Posiedons, Ive done the servicing course with them and they are assemble the same. Yes, its true of using silicone grease it can cause a flash, as for servicing, more care is taken in the prep area from the cleaning and assembly in comparison to standard.

[chrisch]

Originally Posted by jonesor

... I should just replace the O-rings with viton ones?
...

Viton is a DuPont trade name and is a compound that is supposed to withstand high O2 environments for longer than normal O rings. It is not any safer for O2 use. In fact it is now widely abandoned due (I believe) to the highly toxic vapours it gives off when it combusts.

Normal O rings are fine.

Chris

[Tubs]

Twinsetmad

if your using nitrox to 50% then you'll be fine with your regs as they are.

This would be true is the reg is brand new yes, but if the reg has been taken to a dive centre for a service how can you tell if a o2 safe grease was used ? Truth is you can't.

The commonly used o2 grease (christolube) is maybe 10 times the price of silicone grease so chances are silicone may well have been used unless a o2 service was asked for.

So if the reg is new and not been in for a service then yes it should be ok with 50%, if its been serviced then no it may not be, it could be ok but is it worth the chance? There is no AA or RAC at 25m

[jonesor]

Thanks for all your input people

The 1st stage is a couple of years old and been bashed a bit (some chrome scraped off from over zealous tightening with an ill fitting allen key) but has never been serviced. The 2nd stage is brand new.

I'll probably get the 1st stage serviced and O2 cleaned at a reputable shop and use it on my stage.

[telsa]

From previous posts it would seem that there is some thought that the grease used may cause a 'flash' point.

There are three things needed for combustion, oxygen, fuel and ignition - it's refered to as the combustion triangle - take away any one of this three and combustion is not possible!

As far as diving is concerned, oxygen is in the cylinder, hoses and regs, fuel could be any grease used that supports combustion but ignition is also required inside the cylinder, hoses or regs and thats the hard bit and highly unlikely!

The choice of grease is therefore only an attempt to eliminate the fuel from the combustion triangle.

Regards,

Rob

[sccs]

Originally Posted by telsa

From previous posts it would seem that there is some thought that the grease used may cause a 'flash' point.

There are three things needed for combustion, oxygen, fuel and ignition - it's refered to as the combustion triangle - take away any one of this three and combustion is not possible!

As far as diving is concerned, oxygen is in the cylinder, hoses and regs, fuel could be any grease used that supports combustion but ignition is also required inside the cylinder, hoses or regs and thats the hard bit and highly unlikely!

The choice of grease is therefore only an attempt to eliminate the fuel from the combustion triangle.

Regards,

Rob

so you have
oxygen = nitrox
fuel = grease
ignition = pressure

thus completing the combustion triangle,
also exactly the same way a diesel engine works. so the only one u can remove is the fuel, remove either of the other 2 and you cant dive..

[Kev]

Originally Posted by Tubs

Twinsetmad

There is no AA or RAC at 25m

Although, there is lots of water to put your fire out!