How many LP50 twin sets to buy

[inquis]

with a cave fill of 30% nitrox, they come in at 59lbs. Which is 8lbs more than a HP100 for close to a 50% volume increase.

Just to let you know, a 3600 psi fill of Nx30 is 64.2 cuft once compressibility is considered. When doubled, that's about 27% over an HP100 filled to rated pressure.

 

[lowwall]

Just to let you know, a 3600 psi fill of Nx30 is 64.2 cuft once compressibility is considered. When doubled, that's about 27% over an HP100 filled to rated pressure.

Since you seem to have the math at hand, can you tell me how much gas was actually in the HP100 tanks I was getting from Aldora? Fills were 3700psi of EAN32 and 36.

 

[Eric Sedletzky]

Here are five sets of them. I guess I have more than I thought. I know I have a couple sets in my van in Florida.

View attachment 885899

Show off!
Seriously, have you considered seeing somebody about this?

 

[inquis]

Since you seem to have the math at hand, can you tell me how much gas was actually in the HP100 tanks I was getting from Aldora? Fills were 3700psi of EAN32 and 36.

108.9 (EAN32) and 109.5 (EAN36) cuft for both based on the GERG-2004 model by Kunz, et. al.

Subsurface has a pretty good real gas model as well. Hover over the various cylinder cells in the gas table for some additional info from the tooltips. (Not exactly sure how it compares to the above, but I expect them to be close.)

ETA: just checked Subsurface. The compression factors are pretty close, but the ideal size (what goes in the Size column) is off for the HP100. This can be corrected by putting in 106.7 cuft when the pressure is 3442 psi. (This info taken from DGX's page on z-factors.) Then adjust the Start Pressure as appropriate and hover the mouse over the Start Pressure cell to get the true amount.