Adjustment -cont

TM 5-4220-226-14&P (2) Unscrew the dial-a-breath knob (4) all the way out. (3) Insert the inlet valve holder wrench between the inlet valve stem (5) and the piston (6), aligning the blade of the wrench with the small slot in the end of the stem. This prevents stem rotation. (4) Tighten the dial-a-breath knob (4) all the way in and then open it four full turns. (5) Pressure the regulator to between 120 and 150 Ibs of supply pressure. CAUTION It is permissible to loosen the nut (7) no more than 1/8 turn to adjust the lever height. If the nut (7) is loosened beyond this amount, the regulator will not flow to its maximum rate due to insufficient leverage between the lever (10) and the bearing washers on the inlet valve stem. If the nut (7) is adjusted too tight, the regulator will leak. The two opposing blades on the bottom of the lever (1 0) must be in perfect alignment with each other and be free of tool marks or burrs. Normally, if the regulator leaks gas, the nut (7) is too tight and should be loosened until the lever (10) has 1/8 inch of freedom at the end. If the regulator continues to leak, either the inlet valve (1 2) should be changed or the regulator needs a thorough cleaning and lubricating. (6) Adjust the nut (7) until there is 1/8 inch of freedom at the end of the lever (10). (7) Place the diaphragm (3) and cover (2) in place and depress the cover tightly to simulate the clamping action of the clamp (1). (8) Depress the purge button (8) in the center of the cover (2). There should be 1/8 inch of free travel before the button comes in contact with the diaphragm (9). The lever (10) must now be adjusted to this proper height if it is not already correct. The nut (7) can be loosened no more than 1/8 turn to lower the lever (1O) height. The lever (10) must be bent if more adjustment is necessary. 4-13