200 or 300 BAR reg??

[pensacolascott]

I'm going to purchase an HP 120 steel tank and need a new DIN regulator. Do I need to buy a 300 bar or can I just get a 200? I'm asking because the guy at the dive shop was telling about overfilling the tank during the 1st hydro period.

Thanks.

Scott

 

[DiveTub]

The valve on your tank having a 200 or 300 Bar DIN fitting has nothing to do the Hydro testing of your tank.

In fact the valve is not even connected to the tank when the Hydro is performed

 

[pensacolascott]

I guess what I'm asking is whether it's safe to use a 200bar DIN regulator with a tank that may be filled to 4000psi.

 

[DiveTub]

I doubt anyone is going to put more than 200bar into a Cylinder with a 200Bar rated DIN on it. Why not just go the 300bar DIN Valve and save yourself the hassle?

 

[roakey]

First, a 300 BAR regulator can fit either a 200 or 300 BAR valve, but a 200 BAR regulator will ONLY fit a 200 BAR valve. If your 120 is truly a HP cylinder, it will have a 300 BAR valve on it, so bottom-line, get a 300 BAR regulator. If your shop was unable to answer this question for you, you're possibly in for a world of hurt.

Second, traditionally HPs aren't overfilled, and even if they are, you don't get nearly the amount of benefit you get from overfilling LPs. Ultimately HPs aren't overfilled because they fall into the "why bother?" range of benefit.

Third, it's your next statement that leads me to believe that there's some confusion on the part of the dive shop:

"...the guy at the dive shop was telling about overfilling the tank during the 1st hydro period."

This can be taken several ways, all which are incorrect.

The guy could have been talking about the plus rating. This would make him twice wrong, since HP cylinders are not + rated to begin with, and for LP cylinders that ARE + rated, they can be + rated for their entire lifetimes, not just for the first hydro period. The latter is a very, very common misconception that many dive shops have.

Or he could be saying that they only like to truly overfill during the first hydro period. I know LP cylinders that have had several hydros that are merrily being overfilled today, so again even on that level the statement doesn't make any sense.

Be very, very careful when getting steel cylinder information from dive shops. Many have all sorts of misinformation that they dish out constantly.

Hope this helps.

Roak

 

[wb416]

roakey once bubbled...

Be very, very careful when getting steel cylinder information from dive shops. Many have all sorts of misinformation that they dish out constantly.

Hope this helps.

Roak

To reinforce what roakey is saying review the following links. I fell prey to LDS ignorance a couple of years ago when I had an LP95 hydroed. Wish I'd had this info then.

Truth about the plus (+) rating on Steel tanks

Information about the Hydrostatic test

Hydrostatic testing procedures


HTH, wb

 

[rkl]

Most of the regulators sold with a 200 bar threads are capable of handling 300 bar since the only difference is the length of the thread. I know that the first stages of at least Scubapro, Draeger and Poseidon are exactly the same for 200 and 300 bar except the length of the thread. So 4000 psi should´nt be a problem. On the other hand are the tank-valves with the short 200 bar thread only certified up to 220 bar (incl. 10% tolerance), at least in Europe. I believe you will need 300 bar valves and regulators for 4000 psi.