More on HP vs. LP

[k-valve]

Just finished reading the responses on the HP or LP thread. I'm sort of in the same boat. I am just getting into technical diving and would like to purchase my own steel tanks for doubles. I'm not concerned with the weight or size of the tanks as I am with the capacity and whether they are compatible with higher percentage O2 gas mixes. That said, what would be the advantages of having either HP or LP doubles (probably looking at 100 cuft)? Thanks!!

 

[rjack321]

Just finished reading the responses on the HP or LP thread. I'm sort of in the same boat. I am just getting into technical diving and would like to purchase my own steel tanks for doubles. I'm not concerned with the weight or size of the tanks as I am with the capacity and whether they are compatible with higher percentage O2 gas mixes. That said, what would be the advantages of having either HP or LP doubles (probably looking at 100 cuft)? Thanks!!

All cylinders, properly cleaned, are suitable for partial pressure mixing with 02.

 

[TSandM]

Size and buoyancy characteristics are different, and at least if my experience is any indicator, it's good idea to borrow and dive different sets of doubles to see what is comfortable and trims out easily for you, before you spend a lot of money on tanks.

 

[pescador775]

The LP tanks are more suitable for PP filling. The reasons have to do with the ability to transfill oxygen at generally lower pressures than is necessary for HP tanks. Thus, the DIY diver can mix more brew in a LP tank without need for a booster. However, when a stik is employed to pre-blend gas at atmospheric pressure before pumping into the tank then there is no difference that I am aware of.

 

[WPBdiver]

I have both HP 120's and LP 125's. I prefer the LP's mainly because the livaboards and some fill stations that I've used can't fill higher 3000 psi. I have not had a problem with any local fill stations, but did on a few occasions in the Bahamas and once in the Keys. I prefer knowing that no matter where I choose to go, I can get a proper fill.

 

[Skeeter1097]

pescador, I have never heard that before, I well check on it.
A lot of Tk,divers use LP because they can be pumped if you replace the burst valves. If a LP 108 at 2400 is pumped up to 3600 you have about 144 ft of air 144 x 2= 288[ a lot of gas].
If you had a HP 135 at 3700 or 3800 psi you need all of that to get 135. Some places cant fell that so a LP can be to your benefit.
I have LP 108's and enjoy them.

 

[MSilvia]

I am just getting into technical diving and would like to purchase my own steel tanks for doubles. I'm not concerned with the weight or size of the tanks...

In the words of Yoda, "You will be. You will be."

 

[Jason B]

Buy HP.

I dive LP tanks myself. When I cave dive, I have no problem getting them pumped up to 3600psi but at home, that's a different story. If I had bought HP tanks, I could get good fills here in NC.

 

[RAD Diver]

I do'nt know about that Jason I was just in N.C. last weekend & got my LPs filled to 3000psi, not quite the 3500+ I can get here in Va.Beach at my LDS but not bad. You just need to find the right shop.

 

[xiSkiGuy]

pescador, I have never heard that before, I well check on it.
A lot of Tk,divers use LP because they can be pumped if you replace the burst valves. If a LP 108 at 2400 is pumped up to 3600 you have about 144 ft of air 144 x 2= 288[ a lot of gas].
If you had a HP 135 at 3700 or 3800 psi you need all of that to get 135. Some places cant fell that so a LP can be to your benefit.
I have LP 108's and enjoy them.

That 108 is a 108 at 2400 + 10% or 2640psi.