HP 100 single, right hand valve

[fewproud0001]

The 232/300 bar valve issue is not an issue once you get past the marketing hype, nor is the 3442 versus 3500 fill presure.

For what its worth, most cave divers I know are fine with 232 bar valves and manifolds and prefer them over the 300 bar variety. The difference is that 232 bar valves are 5 threads deep while the 300 bar valves are 7 threads deep. They were designed that way to prevent 200 bar regulators from being used on 300 bar tanks as the shorter 200/232 bar reg connection would not see in the deeper 300 bar valve.

That made sense back in the day when some regs were intended for 200 bar pressures and were not approved for use at higher pressures up to 300 bar (4350 psi). However the reality in the US is that gas fills are in the 3300-3600 psi range and most regs handle that pressure just fine so there is no real need to "protect" them from 3500-3600 psi fill pressures.

In any case the difference is not related to the strength of the valve as either valve is more than strong enough for 300 bar pressures. In most cases, I doubt you have more than 3 threads in face to face contact anyway in either valve.

Some divers regard 300 bar valves as less desireable as they are longer (2 more turns to secure the reg), more prone to damage if the tank falls over and have two more threads to trap water that could find its way into the tank during a fill. I don't discriminate against 300 bar valves exactly, in fact I bought one a couple weeks ago, but mostly because it was old stock in the shop (the guy ordered a 300 bar manifold but later decided he really wanted a 200 bar) and as it was not going to sell anytime soon, so I got it for cost about the same as my cost on a pair of 200 bar DIN/K valves.

In N FL the average cave fill is 3600-3700 psi and shops tend to fill both 2400 psi LP tanks to that pressure and use the same pressure for 3442 psi tanks. The 3442 psi story is interesting but not real relevant. What matters is the average gauge is not going to hit 3442 on the money anyway so practically it is a 3500 psi tank that will get 3500 psi fills. In N FL, where cave divng is the norm, most cave divers use some variation fof diving thirds, so a 3500 psi fill woudl require the diver to round down to 3300 psi and use 1100 psi thirds rather than the 1200 psi third he or she would have at a 3600 psi fill pressure, so most shops try to ensure that tanks leave with an honest 3600 psi in them w.hen cool so that usually translates to a 3700-3800 psi initial fill pressure even with a water bath

I have been a dive instructor at the Marine Corps Combatant Dive Course in Panama City for a little over a yr and a half now. We don't use din valves here at all for O/C diving so thanks a lot for a great down and dirty education on those topics. It cleared up a lot of my questions, most of which stemmed from thinking that rated valve pressure directly had something to do with tank strength. Thanks again.

[adam0321]

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In N FL the average cave fill is 3600-3700 psi and shops tend to fill both 2400 psi LP tanks to that pressure and use the same pressure for 3442 psi tanks.

even when you ask them not to.