R
redacted
Guest
If you go with an HP (3500 psi) tank, I assume that means a 7/8-14 valve. Can that valve be adapted to a yoke fitting or are you forced to go with 300 bar DIN?
LP vs HP
- Thread starter RonzoTheGreat
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Jimmer
Contributor
I'm not sure if anyone else has made mention too the fact that it is easier too fill lp tanks with mixed gases. I got a great deal on a hp tank, but other than that all my tanks are lp. Besides that, most LDS charge more for hp fills. Yes the sizes are sometimes more suitable for some, but strategic positioning will usually make up for the size. I've also found that I usually get a light fill in my hp where my lp usually gets a full fill if not a little heavy.
Joe
Joe
limeyx
Guest
Well, thats not really true (unless you accept the fact that the LP tank will be bigger than the HP tank and so "equivalent" to a higher-capacity HP tank)
A "full" fill is irrelevant. What would you prefer, an LP95 "full" to 2640 or an HP-119 "not full" at 3000 psi (although with more gas than the LP95). Since there is (in the US) generally an HP tank of the same physical dimensions as the LP (80/100, 95/119, 104/130) price is a factor, and whether or not you can get "overfills"
simply saying you prefer "full" fills doesn't make sense (like saying lead is heavier than feathers, when you really mean to say lead is more dense than feathers)
or like saying your amplifier "goes to 11"
Oside Jimc
Contributor
Here's my dilemma, I'd like to buy a HP tank (cough **airhog** cough), and since most now come with a "bisexual" DIN/Yoke valve my yoke reg would mount onto the tank, but the first stage is marked "max 232 bar", personally I dont see how the extra 31.8psi of a full HP will really matter, am I being stupid to use it with a HP? Also I'm not sure if a HP119 or HP120 would be a better choice, any input there? (For a 5"10" diver)
OP
RonzoTheGreat
Contributor
.... my LDS fills my HP slowly and i have N E V E R had a fill below 3442 (usually closer to 3500) so there is no cooling down to 3200 or whatever .... so that dilemma is out the window ...
awap, my fabers came with the yoke insert and i removed them for my din regs ...
pvtstash ... you said because you are a big guy, you'll need the extra weight to be negative ... UH UH!!! ... size doesnt matter ... im relatively bigger than you and my dive bud is similar to me ... fat and muscle might make a difference ... but you'll find the more calm you get and comfortable in the water, the easier it will be for you to descend.
pvtstash ... as far as getting "deals" ont he LPS, good luck ... there are deals out there for everything ... dont let that be your determining factor, and also ... you mentioned you will look more "pro-portioned" .... um ... sorry but your looks wont be as important as your trim ... try to rent or borrow various tanks and sizes so you get a better feel for what makes it easier for you to dive trim and comfortable rather than "handling the weight" or "looking proportioned"
pvtstash ... last thing ... if i did it again, i wish i knew it was going to cost me a VIP E V E R Y year for E V E R Y tank i own (on top of the price on hydros which are stupidly expensive around here) ... and keep in mind the more gear you have, the more you are going to pay for servicing, and PLEASE dont think i am caught up on cost, but YOU mentioned going LP over HP to get a better deal ... (dont base it on this)
hope this helps
awap, my fabers came with the yoke insert and i removed them for my din regs ...
pvtstash ... you said because you are a big guy, you'll need the extra weight to be negative ... UH UH!!! ... size doesnt matter ... im relatively bigger than you and my dive bud is similar to me ... fat and muscle might make a difference ... but you'll find the more calm you get and comfortable in the water, the easier it will be for you to descend.
pvtstash ... as far as getting "deals" ont he LPS, good luck ... there are deals out there for everything ... dont let that be your determining factor, and also ... you mentioned you will look more "pro-portioned" .... um ... sorry but your looks wont be as important as your trim ... try to rent or borrow various tanks and sizes so you get a better feel for what makes it easier for you to dive trim and comfortable rather than "handling the weight" or "looking proportioned"
pvtstash ... last thing ... if i did it again, i wish i knew it was going to cost me a VIP E V E R Y year for E V E R Y tank i own (on top of the price on hydros which are stupidly expensive around here) ... and keep in mind the more gear you have, the more you are going to pay for servicing, and PLEASE dont think i am caught up on cost, but YOU mentioned going LP over HP to get a better deal ... (dont base it on this)
hope this helps
On the surface, it is true that an LP tank is easier for gas mixing as if you do partial pressure blending, you can transfill more gas out of the bottle into the tank as the prsure required for a given mix is lower.
However, as indicated above, that point is only valid if you limit the fill pressure to the servcie pressure (or at least to some pressure lower than 3442 psi). So again, if you have an LP tank and a 3442 psi tank of the same exterior dimension and weight, and fill them to the same pressure and same "full" volume, you are going to have to transfill the same pressure of helium and/or oxygen into the tank before topping it off with air to the final pressure. So basically, the argument is a moot point, as if you can only transfill X psi of O2, your maximum final pressure for the mix will be same regardless of whether you are underfilling a 3442 psi tank or overfilling a low pressure tank.
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HP tanks are generally regarded (in the US) as being the 3500 psi tanks sold by sherwood and genesis that used the PITA 7/8" valves. The 3442 psi tanks made by PST (E series) and Worthington (X series) are special permit or exempt tanks and are not usually referred as HP tanks due to their service pressure only being 3442 psi rather than the 58 psi higher 3500 psi.
The difference is really stupid and for all practical purposes meaningless, except for the valve issue and the exemption or special permit they were made under, but for clarity purposes it helps to not call a 3442 psi tank a high pressure tank.
However, as indicated above, that point is only valid if you limit the fill pressure to the servcie pressure (or at least to some pressure lower than 3442 psi). So again, if you have an LP tank and a 3442 psi tank of the same exterior dimension and weight, and fill them to the same pressure and same "full" volume, you are going to have to transfill the same pressure of helium and/or oxygen into the tank before topping it off with air to the final pressure. So basically, the argument is a moot point, as if you can only transfill X psi of O2, your maximum final pressure for the mix will be same regardless of whether you are underfilling a 3442 psi tank or overfilling a low pressure tank.
-----
HP tanks are generally regarded (in the US) as being the 3500 psi tanks sold by sherwood and genesis that used the PITA 7/8" valves. The 3442 psi tanks made by PST (E series) and Worthington (X series) are special permit or exempt tanks and are not usually referred as HP tanks due to their service pressure only being 3442 psi rather than the 58 psi higher 3500 psi.
The difference is really stupid and for all practical purposes meaningless, except for the valve issue and the exemption or special permit they were made under, but for clarity purposes it helps to not call a 3442 psi tank a high pressure tank.
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