SB 740-94-8
2. Smooth trigger movement.
3. Check the disperser gun and hose to
ensure that they are clean. Assemble the hose to the gun
3. The lips of the safety must be able
and connect the hose to the agent tank.
to hold the trigger in the full forward (safe) position.
4. Replace the filler cap.
(b) Equipment required. A regulated air
pressure source (90 psig) and a water tank with a
5. Install the testing gage assembly from
wetting agent in the water.
the M27 Service Kit between the pipe and the cap assembly
connector and the high pressure hose.
(c) Procedure.
6. Fully close the pressure tank valve.
1. Follow the instructions in TM 3-
1040-214-12 to assembly the gun group.
7. Charge the pressure tank with clean
compressed air to 2075-2100 psig.
2. Connect a regulated pressure
WARNING
source of 75 5 psig to the gun.
Do not use a pressure source that
NOTE
cannot be identified, i.e., markings
This test may be combined with the
missing or marking defaced. Refer to
disperser test (see para c(5)), using
the Army Regulation or appropriate
the disperser as the air pressure
technical manual for information on how
source.
to identify the contents of pressure
3. Immerse the forward end of the gun
tanks. A violent explosion can result if
into the water and observe for air bubbles.
compressed oxygen is introduced into
4. Remove the gun nozzle from the
the agent tank of the disperser. An
water and actuate the trigger in a few short bursts,
explosion can also result if hydrogen is
noting the smoothness of the trigger movement. A
introduced into the high pressure tank
rough or "jerky" movement indicates binding of the
assembly when it contains a partial
trigger assembly, absence of lubricant, or a twisted
charge of compressed air.
rubber tube.
NOTE
5. Repeat the leakage test by
Perform steps 8 through 13 on those
immersing the gun nozzle into the water and attempting
items selected for regulated pressure
to depress the trigger with the safety mechanism
test. Perform steps 14 through 17 on
engaged. Do not force the safety latch. Observe for
those items selected for the six-hour
leakage.
stand test.
6. Disassemble and dry the gun group
8. Slowly open the pressure tank valve.
and return the serviceable guns to storage.
9. Inspect the unit for leaks, using soap
(5) M3 disperser assembly, leakage and functional
solution for those parts under air pressure.
check.
10. Observe and record the pressure of the
(a) Requirements.
agent system at the beginning and during the regulated
1. Divide the sample lot in half and
pressure test. Observe and record any abnormal conditions
subject half the lot to a regulated pressure test and the
of the system.
other half to a six hour stand test.
NOTE
If the pressure creeps beyond 90 psig,
2. One hour regulated pressure test.
reset the regulator in accordance with
No leakage in any section is allowed during the
TM 3-1040-214-12 and repeat the test. If
regulated pressure test. The initial agent tank pressure
the pressure again creeps beyond 90
will be between 40 and 45 psig and will not increase to
psig, the regulator must be replaced.
more than 90 psig.
WARNING
3. Six hour stand test. No drop in
Do not point the gun at anyone or
pressure will be permitted in the high pressure system.
anything.
4. Functioning will be prompt and
11. Operate the disperser for three short
positive.
bursts, allowing at least 15 seconds between bursts. Upon
(b) Equipment required.
A regulated air
release of hand pressure from the trigger, air should
pressure source (2200 psig) and a Test Gage Assembly
promptly cease to disperse from the gun.
(identified in Service Kit M27 as B81-6-377, NSN 1040-
12. After the third burst examine the gun for
00-898-1285).
evidence of leakage for a minimum period of one minute.
(c) Procedure.
13. Continue to operate in short bursts until
1. Turn the filler plug assembly and
the air supply is exhausted, allowing at least 15 seconds
relieve any pressure in the agent tanks, then remove the
between bursts. During testing the trigger movement should
filler cap assembly.
be smooth and capable of stopping the air flow on demand.
2. Visually check the interior of the
agent tank to ensure that it is clean. Dirt or foreign
matter can cause gun malfunction.
B-5
