Category Archives: Equipment Specifications

Scuba Cylinder Specifications

Here are some dimensions and specifications for scuba cylinders. This is by no means an exhaustive list. These numbers should be taken as approximate, since equivalent tanks from different manufacturers will differ slightly. The two most common models – the Catalina aluminum 80 and Luxfer aluminum 80 – are highlighted.

  • Weight, full – this is what you will have to be able to lift, in and out of your car, around the dock, and up the boat ladder with all your other gear. Times two for doubles.
  • Weight, empty – this is pretty much irrelevant
  • Buoyancy, empty – this is what you need to weight yourself for, so that you can do a safe free stop at 15 feet at the end of your dive
  • Buoyancy, full  – this is what your BC needs to be able to support when you jump in the water, otherwise you are a “dirt dart” heading straight for the bottom and disaster
Rated
Size
Rated
Pressure
Dimensions Weight Buoyancy +
height diameter empty full empty full
cu.ft. psi inches inches lbs lbs lbs lbs

Aluminum:
Luxfer 63 63.0 3000 21.9 7.25 26.9 31.7 2.5 -2.3
Catalina 80 77.4 3000 25.8 7.25 31.6 37.6 4.1 -1.7
Luxfer 80 77.4 3000 26.1 7.25 31.7 37.4 4.4 -1.4
“Super 80” 80.0 3000 22.9 8.00 35.0 40.9 2.2 -3.7
generic 100 100.0 3300 26.2 8.00 40.8 48.2 3.5 -3.9

LP Steel:
OMS* 66 66.0 2640 21.0 7.00 25.0 28.8 -1.7 -5.5
Faber 72 71.4 3000 20.5 6.84 29.0 34.4 -5.9 -11.3
OMS* 85 85.0 2640 26.0 7.00 31.0 37.7 1 0.0 -6.7
OMS* 98 98.0 2640 24.0 8.00 38.0 45.7 0.0 -7.7
PS** 104 104.0 2640 26.2 8.00 46.0 54.1 -2.5 -10.6
OMS* 108 108.0 2640 26.0 8.00 41.0 48.0 -1.0 -8.0
PS** 120 120.0 2640 33.0 8.00 54.0 63.5 0.0 -9.5
OMS* 121 121.0 2640 29.0 8.00 45.0 54.5 0.0 -9.5
OMS* 135 131.0 2640 30.7 8.00 47.0 58.1 0.8 -10.3
HP Steel: ( DIN valve only )
OMS* 71 71..0 3440 21.3 6.75 24.7 30.1 -1.4 -7.0
OMS* 80 80.0 3440 20.9 7.25 28.6 34.7 -1.7 -8.1
PS** 80 80.0 3500 19.8 7.25 27.0 31.5 -1.0 -5.5
OMS* 100 100.0 3440 25.4 7.25 34.3 41.9 -0.6 -8.4
PS** 100 100.0 3500 23.9 7.25 33.0 40.5 0.0 -7.5
OMS* 119 119.0 3440 24.2 8.00 38.9 47.9 0.2 -9.1
PS** 120 120.0 3500 29.0 7.25 38.0 49.0 1.0 -10.0
Pony & Stage Bottles: ( Aluminum )
Catalina 13 13.2 3000 12.3 4.37 5.4 6.4 -0.4 -1.4
Luxfer 20 19.9 3000 21.9 4.38 8.2 9.5 2 0.1 -1.4
Catalina 30 30.0 3000 20.0 5.25 13.7 16.0 0.0 -2.3
Catalina 40 40.0 3000 24.9 5.25 15.7 18.7 1.9 -1.1
Pony & Stage Bottles: ( Steel )
OMS* 46 46.0 2640 23.0 5.50 17.6 21.6 3 0.0 -4.0
OMS* 20 20.0 2640 19.5 3.90 7.5 9.0 -1.5 -3.0
 
 Notes:
1 with valve, boot, and a good fill – 42 lbs
2 with valve & mounting bracket – 11 lbs
3 with valve, boot, and a good fill – 23 lbs+ at rated pressure

* Faber
** Pressed Steel

Density of dry air = 0.076 lb / cu-ft

Weights and buoyancies that I would consider to be excessive are highlighted in red. In particular, the Faber 72 is ridiculously heavy for its size, and excessively negative, and aluminum 80s are far too buoyant when empty.

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