CHAPTER 7 — Scuba Air Diving Operations
Change A 7-5
7-2.2.2.1
Sizes of Approved Scuba Cylinders. Approved scuba cylinders are available in
several sizes and one or two cylinders may be worn to provide the required quan-
tity of air for the dive. The volume of a cylinder, expressed in actual cubic feet or
cubic inches, is a measurement of the internal volume of the cylinder. The
capacity of a cylinder, expressed in standard cubic feet or liters, is the amount of
gas (measured at surface conditions) that the cylinder holds when charged to its
rated pressure. Table 7-1 lists the sizes of some standard scuba cylinders. Refer to
the NAVSEA/00C ANU list for a list of approved scuba cylinders.
Figure 7-3. Typical Gas Cylinder Identification Markings.
Table 7-1. Sample Scuba Cylinder Data.
Open-Circuit
Cylinder
Description
(Note 1)
Rated
Working
Pressure
(PSIG)
Floodable
Volume
(Cu.Ft.)
Absolute Air
Capacity at Rated
Pressure (Cu.Ft.)
Reserve
Pressure
Steel 72
2,250
0.420
64.7
500
Steel 100
3,500
0.445
106.4
500
Steel 120
3,500
0.526
125.7
500
Aluminum 50
3,000
0.281
48.5
500
Aluminum 63
3,000
0.319
65.5
500
Aluminum 80
3,000
0.399
81.85
500
Aluminum 100
3,300
0.470
105.9
500
Note 1: Fifty cubic feet is the minimum size scuba cylinder authorized. SEAL teams are au-
thorized smaller cylinders for special operations.
DOT3AA2250
Z45015
PST
AB
7-90 +
1. DOT material specification, DOT3AA service
working pressure 2,250 PSIG.
2. Serial number assigned by manufacturer,
Z45015.
3. Identification mark of manufacturer or owner,
PST.
4. Inspector’s stamp, AB.
5. Month and year of qualification test, 7-90.
6. Plus sign (+) indicates air allowable 10% over
service pressure.
DOTSP6498/3000
OR DOT3AL/3000
Z45015
AB
7-90
1. DOT material specification, DOTSP6498 or
DOT3AL service working pressure 3,000
PSIG.
2. Serial number assigned by manufacturer,
Z45015.
3. Inspector’s stamp, AB.
4. Month and year of initial qualification test, 7-90.
STEEL CYLINDERS
ALUMINUM CYLINDERS
