More on HP vs. LP

[ageddiver]

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.

I'm missing something I think? If you compare LP and HP tanks of the same rated volume, you have the option (provided the shop cooperates) of pumping the LP's up for added volume - but not the HP's, at least not to any extent. You must be comparing cranked LP's to rated HP's? If so, that doesn't make sense. You should compare and buy the tanks sized to their rated pressures, and think of the added volume in the LP's as a bonus when you can get it.

Anyhow, someone already said it - the best part about LP's is the ease of doing pp trimix fills, then maybe the extra gas on occasion. If diving mix is not in your future, HP is probably better for weight.

 

[xiSkiGuy]

I'm missing something I think? If you compare LP and HP tanks of the same rated volume, you have the option (provided the shop cooperates) of pumping the LP's up for added volume - but not the HP's, at least not to any extent. You must be comparing cranked LP's to rated HP's? If so, that doesn't make sense. You should compare and buy the tanks sized to their rated pressures, and think of the added volume in the LP's as a bonus when you can get it.

Anyhow, someone already said it - the best part about LP's is the ease of doing pp trimix fills, then maybe the extra gas on occasion. If diving mix is not in your future, HP is probably better for weight.

Or you could look at it in reverse. If you have HP tanks and get an underfill to 3000psi, you still have more gas than the LP tank (at rated pressure) that is a similar external dimension and empty weight.

I would think at some point the empty weight and external dimensions of a tank become an issue for most people. Otherwise we would see more LP-120/HP-149s out there. . .

 

[cerich]

LP is a standard DOT pass, never have to worry about exemptions not being renewed.

It nice to always get a HP fill on the HP vs. some will and some won't on the LP*.

*I do NOT recommend filling any cylinder beyond rated pressure

 

[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!!

Start small, pilots don't learn to fly 747s first time. Don't go for huge doubles. HP100s or LP85s are fine tanks and will serve you well down into the 150-160ft range.

 

[rjack321]

LP is a standard DOT pass, never have to worry about exemptions not being renewed.

Just the stupid plus. It really sucks when you can only get 2400 because someone's too lazy to figure the plus at hydro time and the shop's a stickler for "rated pressures only"