MIL-HDBK-1027/1B
(14) Bleed pressure from vapor compressor
crankcase before removing oil fill plug.
(15) Before undertaking repairs the container or
section of pipe to be repaired must be isolated by closing
valves or physically disconnecting the involved section from
communicating lines, as the situation warrants, followed by
thorough purging with CO2.
(16) Hoses and fittings must be maintained in good
order. Damaged or unsafe hoses must be removed from unloading
area and must not be used for any purpose.
w) The propane interconnection at the device
contractor tie-in point will be a block and vent propane entry
as shown in Appendix J, Figure J-2. This interconnection will
then meet the requirements set forth in NFPA 54 and also the FM
insurance requirements.
x) The two most hazardous events associated with the
gaseous fuel burning trainers are the fuel handling operations
and the accumulation of unburnt fuel in the trainer. The risk
of fuel handling operations is mitigated by strict adherence to
NFPA 58, DM-22, and this handbook. The risk should be further
reduced by having the receiving and storage systems maintained
by the device maintenance contractor or someone experienced with
large propane systems. The danger from accumulated unburnt fuel
in the trainer is adequately eliminated during the occupied
period by a system of ventilation, sensors, and interlocks.
During the unoccupied period, the risk is reduced by natural
ventilation and the proper operation of the key operated
Hands-Off Automatic (HOA) switch in the instructor's station.
Proper operation requires air flushing and purging the crawl
space prior to energizing the crawl space electrical circuits.
(Refer to par. 3.6.4)
y) The maximum fill level (fixed liquid level) gauge
on the top of the tank is inconvenient at times to read. Thus,
a backup variable liquid level rotogauge may be installed in the
center of the tank head. If the float type liquid level gauge
is not operating or if you want to check its accuracy, the
rotogauge may be used. The rotogauge has a manually operated
arm which traces the inside circumference of the tank. When
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