LP tanks & plus ratings

[RDP]

I have had a long running "discussion" with some guys regarding the capacity of LP tanks with + ratings. The topic in question is: If a LP95 / 2400psi tank comes with a + rating, is it at its rated volume at 2400psi or 2640? I don't want to voice my opinion yet, because I don't sway the initial discussion. Please express your thoughts.

 

[MikeC]

Based on everything I have ever been told it is at 2400psi because the "+" is not guaranteed after the primary hydro.

 

[jonnythan]

Rated volume is 95cf at 2640 psi. Lose the + rating, it doesn't hold 95 cf anymore.

 

[mike_s]

A lot of people don't let that + stop them at 2640psi. They pump them up to 3000psi or 3300psi or higher.

 

[MikeC]

Rated volume is 95cf at 2640 psi. Lose the + rating, it doesn't hold 95 cf anymore.

I guess i have been wrong all these years...

 

[Lil' Irish Temper]

A lot of people don't let that + stop them at 2640psi. They pump them up to 3000psi or 3300psi or higher.

I use Faber LP 95's for my doubles that are + rated for 2640 psi

I get mine filled to 3200 psi almost everytime, so it makes them jump from 95 cu. ft. of backgas to 115 cu. ft.

Not that I'm telling anyone to do that, it's just what I do . :11:

 

[RDP]

I was curious to see how the consensus of those on this board compared to that of the local dive guys. It seems like the split is about the same.

For those of you that overfill, shame on you. (This includes myself. ) I agree the volume rating includes the + pressure. I sent a letter to Faber, and they stated their volume is determined including the + rating. Therefore, a LP95 holds 95cu.ft. at 2640psi (86.4cu.ft. at 2400).

 

[Caver95]

so you mean when I fill mine to 4 grand they are hold a lot.

 

[RDP]

so you mean when I fill mine to 4 grand they are hold a lot.

Hell yeah, about 144cu.ft. each! I haven't had the balls or the burst disk to go that high with mine. I understand in the UK, these same Faber tanks are used at 4500psi on a regular basis.

 

[roakey]

I was curious to see how the consensus of those on this board compared to that of the local dive guys. It seems like the split is about the same.

It's 2640 for sure. Who writes the glossy brochures that claim cylinder capacity? -- the marketing folks. You think they'll miss an opportunity to mislead the customer? Of course not!

This was a common problem “in the old days” when your steel 72 would lose its + rating – 72 doesn’t sound that much different than 80, but when you dove with your AL80 buddies with your non-+ rated 72, it was actually about a 65...

Roak