HP PST 100 vs HP Worthington 100?

[gcbryan]

My buddy has a 100 cu ft HP PST steel tank as well as a 100 cu ft HP Worthington steel tank. They both appear to have the same external diameter but the Worthington is noticeably shorter and yet they are both rated as holding 100 cu ft.

How can that be? Different tank thicknesses?

 

[Warren_L]

Are you sure they are both 100 cu ft tanks? The specs I was just looking at say both the PST and Worthington HP 100s have almost the same dimensions. 7.25" diameter, 24" height, same working pressure.

 

[Peter_C]

This subject was just brought up and no one seems to have come up with an answer yet.
http://www.scubaboard.com/showthread.php?t=135067

 

[Jim Ernst]

i have the pst 119 and worthinton 119 both hp tanks, and yes the worthinton is about an inch and a half shorter, dont know but i love both tanks and dont see any other differance but the slight hight dif!!!!

 

[JustinW]

I don't know for sure, but have you considered the profile of the boot? Also if the wall thicknesses are different internally then that will have an effect.

 

[PfcAJ]

Measure the neck.

 

[alpaj]

Applying some math I think that it's a matter of diameter vs height. When you do the math, an increase in height by one inch for example does not add nearly as much volume as an inch increase in diameter. So that one inch height difference could countered by a very slight difference in diameter (such as thickness further down the cylinder). That's what I think. Hence why you can get some really high capacities in the short but fat cylinders. Or maybe capacity on the table was measured at slightly different conditions of temperature etc.

 

[Leadking]

Nominal volume on a 100 cf Worthington cylinder is 745 ci (cubic inches)

3442/14.7=234x745/1728=100.88 cf

We have done volume checks against hydro data and can confirm the volume at rated pressure is within 2%

Lee
www.seapearls.com

 

[spectrum]

I think Leadkng mentioned a week or 2 ago that the Worthington has some extra steel down in the bottom.

Pete