Fuel Cells Testing - Piper PA-44-180 SEMINOLE Maintenance Manual

TESTING FUEL CELLS.
Either of the following test procedures may be used to detect leaks in the bladder cells:
1. Soap Suds Test.
A. Attach test plates to all fittings.
B. Inflate the cell with air to a pressure of 1/4 psi MAXIMUM.
C. Apply a soap and water solution to all repaired areas and any areas suspected of leakage. Bubbles will
appear at any point where leakage occurs.
D. After test. remove all plates and wipe soap residue from the exterior of the cell.
2. Chemical Test.
A. Attach test plates to all fitting openings except one.
B. Make up a phenolphthalein solution as follows: Add 40 grams phenolphthalein crystals in 1/2 gallon
of ethyl alcohol. mix, then add 1/2 gallon of water.
C. Pour ammonia on an absorbent cloth in the ratio of 3ml per cubic foot of cell capacity. Place the
saturated cloth inside the cell and install remaining test plate.
D. Innate the cell with air to a pressure of 1/4 psi MAXIMUM, and maintain pressure for fifteen minutes.
E. Soak a large white cloth in the phenolphthalein solution, wring it out thoroughly, and spread it
smoothly on the outer surface of the cell. Press the cloth down to insure detection of minute leaks.
F. Check the cloth for red spots which will indicate a leak. Mark any leaks found and move the cloth to a
new location. Repeat this procedure until the entire exterior surface of the cell has been covered. If
red spots appear on the cloth. they may be removed by re-soaking the cloth in the solution.
G. The solution and test cloth are .satisfactory only as long as they remain clean. Indicator solution that is
not in immediate use should be stored in a closed rustproof container to prevent evaporation and
deterioration.
After the test. remove all plates and test equipment. Allow the cell to air out.
In conducting either text outlined above, the cell need not be confined by a cage or jig, providing the 1/4 psi
pressure is not exceeded.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— Note —
The chemical test is the more sensitive and preferred test.
2B8
2 8 - 11 - 1 6
Page 28-10
Revised: May 15, 1989