Legend LX or Apex?

[cnidae]

Chaos once bubbled...
Some interesting background info: Aqua Lung is owned by Air Liquide, one of the world's largest industial gas suppliers. I don't think a company like that would be mistakingly using EPDM in high O2 environments.

I was told that this is why there not approved for 100%. Air Liquides standards for over 40% are supposeably much higher than the other companies.

 

[Chaos]

I know that they do not approve of their regs being used with over 40% O2, but the Calypso O2 uses the same time O-rings and it's perfectly suited for 100%. Now I know this may have to do with gas routing and adiabatic compression, but still, the materials are the same. EPDM in 100% O2.

 

[globaldiver]

I would go with the Apeks. It has a rock solid performance and reputation. It is easy to service, and is a superb regulator to have during cold water diving.

Sincerely

Anders

 

[marco]

I don't know if it is true but I have been told that is quite safe to use normal O rings for any 100% O2 reg. They should easily last one year, so if you replace all the O rings when your regs are serviced anually there is no problem. Manufacturers will never admit this due to liability problems if somebody waits too long to get their regs serviced and the O rings do fail.

But as I said this is waht i have been told so not sure if it is true.

 

[BigJetDriver]

marco once bubbled...
I don't know if it is true but I have been told that is quite safe to use normal O rings for any 100% O2 reg. They should easily last one year, so if you replace all the O rings when your regs are serviced anually there is no problem. Manufacturers will never admit this due to liability problems if somebody waits too long to get their regs serviced and the O rings do fail.

But as I said this is waht i have been told so not sure if it is true.

Admittedly, Marco, there is a lot of gobbledy-gook bandied about concerning the use of high pressure O2. If you go back to basics, however, some things will make sense.

Fire requires (1) an ignition source, (2) fuel, and (3) an oxidant. In the case of high pressure O2 use, we have plenty of oxidizer. The fuel can be almost anything, but in the pathways we are talking about, the lubricant is the most vulnerable, followed by the O-rings, then such things as high pressure valve seats. The ignition source is the energy generated by the rapid movemnt of the O2 molecules themselves.

While there are some few who argue, most agencies, organizations, and trainers agree that up to 40% O2, standard SCUBA regulators, tankage, and equipment is OK! Beyond that point is where things get touchy.

Since most nitrox mixing is done via the partial pressure method in which 100% O2 is decanted into a cylinder, this brings about the requirement for O2 cleaning the cylinder, and the use of O2 compatible O-rings and lubricants in the valve.

If you then attach a SCUBA high presssure demand valve (regulator) to a tank with a high O2 concentration, for deco purposes for instance, this brings about the requirement for O2 compatible O-rings and lubricant in at least the high pressure side, i.e. the first stage. Remember, the high pressure side is where you have the most chance of having the molecules moving fast enough to generate enough thermal energy to cause ignition.

Oxygen fires are really impressive, especially when metal parts of things begin to burn. It is easy enough to set things up properly, and to be safe. DON'T PLAY WITH FIRE, KIDS!!=-)