   | | | Avon
Crank Soak Wash Procedure |
| | Eliminate
Performance Losses Through Regular Cleaning
Avon
gas generators are often operated in an atmosphere of fog, industrial pollution
or high salt density. Contamination of the compressor resulting from these conditions,
if allowed to go unchecked, will result in a loss of compressor efficiency leading
to a reduction in performance.
Compressor cleaning at regular intervals
or when deterioration in performance becomes apparent can correct the effects
of this contamination. The most effective method of cleaning the compressor is
the crank soak procedure detailed below.
Washing
Procedure
1.
Allow the engine to cool down for a period of 30 minutes. During the engine cooling
down period fit the Inlet Guide Vane (IGV) setting tool lever, part number GT
14107, to the master IGV. Using the lever, pull the IGVs to the fully open position
and lock in place by fitting the lever-retaining pin into the master IGV bush.
The pressure of the IGV ram will hold the lever arm against the pin and keep the
IGVs fully open.
2.
Check drainage holes, located on the underside of the compressor casing, and crank
wash ring nozzles are unrestricted. This can be achieved by the use of a stiff
piece of wire. Place a clean tray under the drain holes.
3.
Using a lint free cloth and diluted solution of the washing fluid hand clean the
intake flare, nose cone, front bearing housing, IGVs/IGV outer bushes and '00'
stage compressor blades. The washing fluid must be diluted to the same constituency
as detailed for crank washing. Ensure all health and safety regulations, for handling
and inhaling of the washing fluids are adhered to, in line with the washing fluid
manufacturer recommendation i.e. wear rubber gloves, eye protection and rubber
or PVC aprons. Any contamination to the skin should be immediately washed off
with water.
4.
Mix 2½ gallons of the cleaning additive with the appropriate amounts of
water as detailed in Avon Service Bulletin No.84.
5.
With the ignition and fuel supply OFF, initiate a start cycle. As soon as the
gas generator starts to rotate inject the cleaning mixture into the compressor
over a 2-minute period. Cranking speed will depend on starter motor fitted typically
800 - 1500 rpm.
6.
Check the cleaning fluid is draining from the drain holes located on the underside
of the compressor. As detailed in paragraph No 2, if restricted, clear with a
stiff section of wire.
7.
Mix a further solution of the cleaning additive and inject this as soon as possible
following the first solution wash. Allow the compressor to soak and drain for
15 minutes.
8.
During the soak and drain period inspect for any residual contamination on the
intake flare, front bearing housing, IGVs and visible stages of the compressor.
Hand clean any evidence of contamination with a soft brush. Remove the locking
pin from the IGV setting lever and using the lever exercise the IGVs checking
for freedom of movement. Re-fit the retaining pin ensuring the IGVs are in the
fully open position.
9.
Carry out the first rinse cycle. As soon as the gas generator starts to rotate
inject 2½ gallons of rinsing water into the compressor over a 2-minute
period. Allow to soak and drain for 15 minutes.
10.
Carry out further rinse cycles until the rinse fluid is visibly clean. If it is
found after 2 rinse cycles the fluid is still dirty then carry out a further solution
wash, as detail above, followed by a series of rinse washes until the water is
visibly clean.
11.
Remove the IGV setting tool.
12.
Carry out a 5-minute dry out run at idle speed to remove any residual washing
fluid in the compressor.
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