|
| |
TM 9-254
3-20.
Time Cycles - Continued
b.
Maintenance personnel will purge and charge fire control materiel being repaired whenever the repair function
affects internal sealing.
c.
For maintenance of materiel in storage refer to TM 740-90-1 (Administrative Storage) and for time cycles
refer to SB 740-95-601 (Storage Serviceability Standards for USAWECOM Materiel).
Section IX. PURGING AND CHARGING FIRE CONTROL EQUIPIENT
3-21.
General.
This section contains general procedures for purging and charging of fire control equipment. Insure that all preformed
packings, gaskets, and seals have been properly installed into the instrument. Refer to the appropriate technical manual
for a list of repair parts for the fire control instrument being repaired. Apply sealing compound to the threads of setscrews
and air valve stem, around level vial mounting, and other places that may leak internal pressure while being leak tested.
For the purpose of demonstration, the M118 series Elbow Telescope is used as the instrument being sealed and leak
tested.
3-22.
Purging and Charging.
a.
Purging (fig. 3-47). Purge the fire control instrument (M118 series Elbow Telescope) as follows:
(1)
Perform the setup of the single stage pressure test fixture as described in paragraph 3-18a.
(2)
Remove the inlet port cap (3) and outlet screw (5).
(3)
Attach the free end of the hose assembly (6) to the inlet port (4).
(4)
Turn pressure regulator valve (2) clockwise until low pressure gage indicates 5 psig. Maintain pressure
for 15 minutes.
(5)
Turn pressure regulator valve (2) counterclockwise to off.
(6)
Apply sealing compound to threads of outlet screw (5) and install.
b.
Charging (fig. 3-47). Charge the fire control instrument (M118 series Elbow Telescope) as follows:
(1)
Turn pressure regulator valve (2) clockwise until low pressure gage (1) indicates 1 psig. Maintain
pressure for 1 minute.
(2)
Turn pressure regulator valve (2) counterclockwise to off.
(3)
Apply a soap solution to all sealed joints and screws.
(4)
Observe the low pressure gage (1) and the telescope for 5 minutes minimum. If the pressure drops or
bubbles appear, refer to the appropriate manual for maintenance procedures.
(5)
Remove hose assembly (6) and install inlet port cap (3).
3-48
|
