Dive Gear Express XTRA Second Stage, Руководство по обслуживанию

Страница: 24 / 25

7. Testing for Cracking Pressure
(1) Cracking pressure is the effort required to depress the lever and allow air to flow through the second
stage. It is measured in inches of water. A Magnehelic is one method of doing this. The gauge is attached to
the second stage, and a normal breath is taken. The gauge measures the amount of effort.
(2) Another way is to take the second stage, and using a ruler attached or held to the stage, to place it
carefully into a water container and note where on the ruler the air begins to flow. Not always as accurate
as a magnehelic, but yields acceptable results.
Caution Note:
Do not leave the In­Line Adjustment Tool attached when submerging the second stage!
Connect the stage to the LP hose directly. The tool is not meant for in­water use!
(3) Cracking pressure should initially be set at 1 to 1.2 inches of water. This will account for the decrease that
will be seen as the regulator is used. As the seat begins to form the groove between it and the orifice knife­
edge, cracking pressure will decrease. If necessary, it can be increased by removing the rubber plug on the
Adjustment screw and increasing spring tension by turning the Adjustment Spring clockwise. The benefit of
this is that the orifice/LP seat sealing connection is not as likely to be negatively affected.
(4) General Troubleshooting – Not all possibilities may be noted.
No airflow Check supply pressure, orifice too tight, lever not
seated and has dropped,
Free Flowing Orifice adjusted too loose, LP seat bad, excessive IP
Hard to inhale Lever bent or restricted, adjusted with a too high
cracking pressure
Wet breathing Cracked case, bad diaphragm – exhaust, bad
diaphragm – main, cracked case
Purge button hard to press Debris in purge button, bad spring