18
Micra ADJ Second Stage Service & Repair Manual
© 1997 U.S. Divers Co., Inc.
3.
When purge flow is correct, remove the second-stage from the
mouthpiece adapter on the flow test bench. Shut the valve of
the test bench, and purge the second stage to depressurize the
system. Remove the regulator.
EXTERNAL LEAK TEST
1.
After disconnecting the regulator from the flow bench, con-
nect to a scuba cylinder filled to approximately 3,000 psi.
Open the cylinder valve to repressurize the regulator, and
submerge the entire system in a test tank of clean water.
2.
Observe any bubbles arising from the submerged regulator
over a one minute period. The recommended time is neces-
sary due to slower bubble formation that occurs in smaller
leaks. Bubbles indicate a leak, which requires that the system
must be disassembled at the source to check sealing surfaces,
assembly sequence and component positioning in order to
correct the problem(s).
NOTE: Extremely small leaks may be better detected by
applying a soap solution or Snoop™ to the leak area.
Bubble streams will indicate the source of the leak. Before
disassembling to correct any leaks, rinse the entire regulator
thoroughly with fresh water and blow out all residual mois-
ture with filtered, low-pressure (50 psi) air. Disassemble and
remedy the problem, referring to Table 1 - Troubleshooting.
SUBJECTIVE BREATHING TEST
1.
While the regulator is connected to a cylinder containing
3,000 psi and pressurized, turn the second stage adjustment
knob completely out counterclockwise to the full positive
position, and verify that a slight leak of airflow is present.
2.
Slowly turn the adjustment knob in clockwise to verify that
the airflow stops between
2-w
turn.
3.
Turn the adjustment knob completely in clockwise to the full
negative position, and depress the second stage purge to
ensure that an adequate volume of air needed to clear the
second stage flows through the mouthpiece..
4.
Turn the adjustment knob back to
2-w
turn negative, and
breathe from the second stage. A properly serviced and
adjusted regulator should deliver air upon deep inhalation
without excessive inhalation effort, freeflow, or “fluttering” of
the second-stage diaphragm. When exhaling, there should be
no fluttering or sticking of the exhalation valve. If any of
these problems occur, refer to Table 1 - Troubleshooting.
This concludes annual service procedures for the Micra ADJ
