10
Impulse Second Stage Service & Repair Manual
© 1997 U.S. Divers Co., Inc.
correct alignment, press the box top evenly onto the box
bottom and turn 45 degrees clockwise, until the extended
portion is centered directly over the inlet (see Fig. 16b).
31. Install the mouthpiece(15) onto the box bottom, and lightly
fasten a clamp(16) onto the groove of the mouthpiece. Turn
the clamp so that the locking tab is facing toward the inlet side
of the box bottom, and pull the clamp sufficiently snug. Snip
the extra length with a small pair of scissors or wire cutters.
This concludes the reassembly of the Impulse second
stage. Refer directly to the following section, titled Final
Adjustment & Testing.
Final Adjustment & Testing Procedures
NOTE
: Before performing the following procedure, refer to
Table 5, titled Test Bench Specifications - Impulse 2nd Stage
CAUTION:
Prior to adjusting and testing the Impulse sec-
ond stage regulator, the accompanying first stage must be
correctly serviced, adjusted to a stable intermediate pressure
of 140 psi , and fully tested. Refer to either the Conshelf SE
Service Manual (P/N 7802-08) or the SEA Service Manual
(P/N 7802-12) before attempting to perform the adjustment
and testing of the Impulse second stage.
1.
Thread the male fitting of the IP hose into the preferred low
pressure port of the first stage, and apply a torque wrench with
11/16" cr
ow-foot to tighten to 40 inch-pounds (
±
2
).
2.
Connect an intermediate pressure test gauge (P/N 1116-10) to
the first stage via a separate low pressure hose.
3.
Attach the female fitting of the second stage low pressure hose
to the In-Line Adjustment Tool (P/N 1001-95) by mating the
swivel nut onto the male threaded end of the tool. Turn the
swivel nut clockwise until finger snug (see Fig. 17).
4.
Pull back the knob of the tool to retract the adjusting stem,
and mate the female threaded end of the tool onto the second
stage inlet fitting. While holding the tool secure, turn the
second-stage clockwise until lightly snug.
5.
Turn the second stage adjustment knob completely out
counter-clockwise, and set the vane adjustment switch to the
"MIN" position (see Fig. 18).
6.
Connect the first stage to a filtered air source of 3,000 psi.
NOTE:
The preferred air source for final tuning and testing is
a flow bench with accurately calibrated gauges. If a flow
bench is not available, a scuba cylinder may be used, follow-
ing the subjective breathing test provided on page 13.
7.
Slowly open the valve of the air supply to fully pressurize the
regulator. Press the knob of the inline adjustment tool inward,
Fig. 17 - In-Line Adjustment Tool Connection
Fig. 18 - Preliminary Settings
Fig. 16a - Boxtop Installation - Step 2
