TM 5-4220-226-14&P
CAUTION
Locknut (17) should always be replaced with a new locknut if
removed from the inlet valve.
(3) Place washer (23), lever (22), and spacer (21) onto the shaft of the inlet valve (18). Screw a new
locknut (17) onto the inlet valve until the inlet valve threads protrude slightly (about two threads) past
the nut.
(4) Lubricate new preformed packing (16) with silicone lubricant. Install inlet nipple (15) with packing
(16) into the regulator body.
(5) Lubricate piston (1 3), spring set (I 2), and spacer (11) generously with silicone lubricant. Insert
piston, spring set, and spacer into the adjustment tube of the regulator body.
(6) Thread shaft (7) into tube of regulator body. Slide washer (9) and preformed packing (8) onto shaft
(7).
(7) Slide packing nut (6) over shaft (7) and thread onto tube of regulator body.
(8) Fit knob (5) onto shaft (7) and align with holes of shaft. Support knob on block of wood and install
retaining pin (10) by tapping it through knob and shaft.
CAUTION
Do not over tighten inlet valve nut as this will cause
malfunctioning of demand regulator.
(9) Tighten inlet valve nut (17) until lever (22) is snug with no play.
(10) Check dial-a-breath knob (5) for free rotation and tighten packing nut (6) accordingly.
(11) Replace diaphragm (4) into regulator body.
(12) Install regulator cover (3) and secure with clamp (2) and screw (1).
g. Installation
(1) Lubricate new preformed packing (5) and packing groove on regulator body (3). (Ref III, para 4-1
5b).
(2) Mount regulator body on helmet and install new preformed packing (5) and regulator mount nut (4).
NOTE
Do not tighten mount nut until the bent tube is installed on the
inlet cap and side block body.
(3) Refer to illustration in paragraph 4-15b and thread bent tube (1) nut on regulator inlet cap of demand
regulator. Do not tighten.
(4) Thread bent tube nut onto side block (2). Tighten side block bent tube nut, then regulator mount nut,
and regulator end bent tube nut.
4-17
