U.S. Navy Diving ManualVolume 5
PRESSURE TEST FOR USN RECOMPRESSION CHAMBERS
All U.S. Navy Standard recompression chambers are restricted to a
maximum pressure of 100 psig, regardless of design pressure rating.
A pressure test shall be conducted on every USN recompression chamber (except TRCS):
When initially installed
When moved and reinstalled
At two-year intervals at a given location
Performance of the test and the test results are recorded on a standard U.S. Navy Recompres-
sion Chamber Air Pressure and Leak Test form (attached).
The test is conducted as follows:
Pressurize the innermost lock to 100 fsw (45 psig). Using soapy water or an equivalent
solution, leak test all shell penetration fittings, view-ports, dog seals, door dogs (where
applicable), valve connections, pipe joints, and shell weldments.
Mark all leaks. Depressurize the lock and adjust, repair, or replace components as
necessary to eliminate leaks.
View-Port Leaks. Remove the view-port gasket (replace if necessary), wipe clean.
Acrylic view-ports should not be lubricated or come in contact with any
lubricant. Acrylic view-ports should not come in contact with any volatile
detergent or leak detector (non-ionic detergent is to be used for leak test).
When reinstalling view-port, take up retaining ring bolts until the gasket
just compresses evenly about the view-port. Do not overcompress the
b. Weldment Leaks. Contact appropriate NAVSEA technical authority for guidance on
Repeat steps 1 and 2 until all the leaks have been eliminated.
Pressurize lock to 225 fsw (100 psig) and hold for 5 minutes.
Depressurize the lock to 165 fsw (73.4 psig). Hold for 1 hour. If pressure drops below 145
fsw (65 psig), locate and mark leaks. Depressurize chamber and repair leaks in
accordance with Step 2 above and repeat this procedure until final pressure is at least 145
fsw (65 psig).
Repeat Steps 1 through 5 leaving the inner door open and outer door closed. Leak test
only those portions of the chamber not previously tested.
Figure 22-13a. Pressure Test for USN Recompression Chambers (sheet 1 of 3).