(2)
Any operator who knows of fire extinguishing agents that are not specified in Figure 201 should give their local Pratt & Whitney representative the technical data and Material Safety Data Sheets for those agents. This data should be sent to Pratt & Whitney Customer Support in East Hartford, CT.
(3)
The most important problem with dry powder chemicals being discharged into the engine is corrosion during subsequent engine operation. These materials can be very bad to hot section parts. These dry powder chenicals cause chemical reactions during engine operation.
(4)
Stainless steel alloys, nickel base alloys (coated or uncoated), and cobalt base alloys have a high degree of susceptibility to chemical corrosion. Chemical corrosion can occur at temperature levels less than those of the engine operating range. Titanium, aluminum, magnesium, cadmium plated and nickel-cadmium plated low alloy steels show no corrosion from bicarbonate compounds at engine operation temperature levels.
(5)
Products of decomposition which result from the use of Halon 1301 fire extinguishing agent will include certain acids which can have a small corrosive effect on gaspath materials when exposed to high temperatures. Turbine airfoil coatings can degrade from Halon 1301 contact at 1800 degrees F (982 degrees C) for short exposure if discharged directly into the core of the engine from a ground unit. Onboard nacelle fire extinguishing systems (Halon 1301) on turbofan engines, however, do not discharge directly into the core engine but rather into the nacelle compartment which would not result in contact with the turbine airfoils.
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MAINTENANCE MANUAL
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NOTES:
* EXTERNAL WASH ONLY BY SPOP 1 DO NOT COMPRESSOR WASH.
A/R -AS REQUIRED, INSPECT TO DETERMINE THE EXTENT OF CONTAMINATION WHICH WILL DETERMINE EXTENT OF DISASSEMBLY.
(1)
VACUUM -VACUUM AS SOON AS POSSIBLE TO REMOVE LOOSE DEBRIS TO AVOID IMBALANCE OR INTERFERENCE OF MOVING PARTS FROM RESIDUE DEPOSITS.
(2)
FREEDOM OF MOVEMENT CHECK - IF FOAM OR DRY FIRE EXTINGUISHER CHEMICALS WERE USED, CHECK FOR IMBALANCE OR INTERFERENCE BETWEEN MOVING PARTS FROM RESIDUAL DEPOSITS.
(3)
INTERNAL WASH/EXTERNAL WASH - DO A COMPRESSOR WASH TO REMOVE DEPOSITS. IF EXTERIOR OF ENGINE CAME IN CONTACT WITH CHEMICALS, CLEAN THE EXTERNAL PARTS OF THE ENGINE WITH SPOP 1.
(4)
VISUAL/BORESCOPE INSPECTION - DO COMPLETE EXTERIOR VISUAL INSPECTION AND AN INTERNAL BORESCOPE INSPECTION OF PARTS SUSPECTED TO HAVE BEEN IN CONTACT BY CHEMICAL FIRE EXTINGUISHER. USE APPLICABLE INSPECTION LIMITS.
(5)
VISUAL INSPECTION - DO A VISUAL INSPECTION FOR CONTAMINATION.
(6)
ENGINE SHOP DISASSEMBLY - DO A VISUAL INSPECTION OF ALL PARTS SUSPECTED TO HAVE BEEN CONTACTED BY CHEMICALS. MAKE SURE ENGINE PARTS ARE FULLY CLEANED BEFORE INSPECTION. REFER TO PW4000 ENGINE MANUAL AND PW4000 CIR MANUAL. USE APPLICABLE INSPECTION LIMITS.
Fire Extinguishing Agents
Figure 201 (Sheet 2)
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