Piper Navajo PA-31 Service Manual page 979

PIPER NAVAJO SERVICE MANUAL
d.
Inspection of the regulator may be effected by introducing into an outlet a mask connector to
which is attached a 100 psi gauge. With one other outlet flowing through a plugged in mask, the indicated
regulator output pressure shall be not less than 45 psig at sea level with 200 psig supply cylinder pressure. It
should be noted that the permissible leakage through the 1/16 diameter vent hole in the side of the upper
regulator housing is 10 cc/min. maximum, when the regulator is turned on. There shall be no external
leakage anywhere on the regulator when it is turned off. All fittings shall be leak free.
14-7. TESTING FOR LEAKS. Apply detector fluid type CD-1 solution or its equivalent. The solution
should be shaken to obtain suds or foam. The suds or foam should be applied sparingly to the joints of a
closed system. Look for traces of bubbles. No visible leakage should be found. Repair or replace any
defective parts and retest system. With the system pressurized to service pressure, further test can be made.
The rate of any leak should not exceed one percent of the total supply per 24 hour period. All traces of the
detector fluid should be wiped off at the conclusion of the examination.
14-8. MAINTENANCE.
a. Check that all lines have sufficient clearance between all adjacent structures and are secured in
place. Also check the cylinder to be sure it is securely mounted.
b. Check the cylinder for the ICC identification number and for the date of the last FAA inspection
and test.
c.
If cylinder is completely empty, it must be completely disassembled and inspected in an FAA
approved facility before recharging.
d. Any lines that are defective should be replaced with factory replacements.
e. Clean all lines and fittings as described in Paragraph 14-9.
f.
Use Ribbon Dope Thread Sealant (Permacel 412) on male ends of fittings only. Wrap thread in
direction of thread spiral, beginning with the second thread on the fitting. Avoid getting any sealant into
the lines.
g. Refer to FAA Manual AC43.13-1A for more details.
14-9. CLEANING OPERATIONS. To remove oil and grease from tubing and fittings, one of the following
cleaning methods may be used:
a.
First Method:
I.
A vapor degreasing with stabilized trichlorethylene conforming to specification MIL-T-7003
shall be used.
2. Blow tubing clean and dry with a stream of clean, dried, filtered air. Care shall be taken to
insure that the interior of the tubing and fittings are thoroughly cleaned.
b. Second Method:
1.
Flush with naptha conforming to specification TT-N-95.
2.
Blow clean and dry off all solvent with water pumped air.
3.
Flush with anti-icing fluid conforming to specification MIL-F-566 or anhydrous ethyl
alcohol.
4. Rinse thoroughly with fresh water.
5.
Dry thoroughly with a stream of clean, dried, water pumped air or by heating at a
temperature of 250" to 300 F for a suitable period.
6. The solvents may be reused provided they do not become excessively contaminated with oil.
This condition shall be determined as follows:
(a). Evaporate 100 milliliters of the liquid to dryness in a weighed glass dish. Evaporation
may be accomplished by heating at 200 F for one-half hour.
Reissued: 10/12/79
ACCESSORIES AND UTILITIES
5E6