PIPER COMANCHE SERVICE MANUAL
04/01/09 II - HANDLING AND SERVICING
1B19
2-7a. Torque Requirements. (PIR-PPS20015-1, Rev. W.)
CAUTION: DO NOT OVERTORQUE FITTINGS.
Table II-I lists the torque values for flared fittings of various sizes and material.
NO
TE: When installing flared fittings, verify that male threads are properly lubricated.
The torque values given in Table II-IIA are derived from oil-free cadmium-plated threads and are
recommended for all airframe installation procedures where torquing is required, unless other values are
specified in subject section. Engine torque values are found in the latest revision of Lycoming Service
Table of Limits SSP-1776; and propeller torque values are found in Sections VII, VIIA, VIIB and VIIC.
NO
TE
: If normal operation requires movement between any of the components being clamped together,
tighten the nut (or bolt) enough to insure intended operation of the assembly.
A. Calibrate the torque wrench periodically to assure accuracy, and recheck frequently.
B. If the fastener, screw, or nut is listed in Table II-IIA, but the mating fastener is not listed, tighten
only to the low end of the torque range specified for the listed fastener. In addition, the following
limitations shall apply:
(1) Fastener and nut threads shall be clean and dry (free of lubricants). If the subject
chapter/section requires the fastener and/or nut to be lubricated prior to tightening and does not
specify a torque requirement, use the Table II-IIA torque range reduced 50 percent.
(2) Table II-IIA, Sheet 1, shall be used for free running nuts, provided minimal friction drag is
determined as specified below.
TABLE II-II. FLARE FITTING TORQUE VALUES (PIR-AC65-9A.)
Torque — Inch-Pounds
Tubing Hose End Fitting
OD and
Inches Aluminum Alloy Tubing Steel Tubing Hose Assemblies
Minimum Maximum Minimum Maximum Minimum Maximum
1/8 20 30 ——— ——— ——— ———
3/16 30 40 90 100 70 120
1/4 40 65 135 150 100 250
5/16 60 85 180 200 210 420
3/8 75 125 270 300 300 480
1/2 150 250 450 500 500 850
5/8 200 350 650 700 700 1150
3/4 300 500 900 1000 ——— ———
7/8 500 600 1000 1100 ——— ———
1 500 700 1200 1400 ——— ———
1-1/4 600 900 ——— ——— ——— ———
1-1/2 600 900 ——— ——— ——— ———
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