Fuel access plate torque value?

[rv6ehguy]

Good day fellow RVators,
I’m about to close up my fuel tanks using the ProSeal only technique on the fuel access plates and I was wondering what torque value to use for the AN515-828 (8/32”) screws. Is it the standard 12-15 inch pounds or does the value change because nut plates are being used to hold the access plates onto the end rib. Thanks for your time.
John Van Lieshout
[email protected] wz(underscore)bang(at)hotmail(dot)com
416.948.5626
RV6A QB 85% complete
C-FMYM (reserved)
AeroSport Power IO375-M1S 195 hp
(Still need a propellor)
2 screen Garmin touch screen efis suite

 

[terrye]

The torque value of 12-15 lb-in for #8-32 screws in AC43.13 assumes no prevailing torque (eg. from a nutplate or a locknut). I suggest you make up a test piece with 3 or 4 nutplates and use a deflection type torque wrench to establish the prevailing torque of the screw going into the nutplate. Bottom the screw out and then add 12-15 lb-in. This should be the torque you apply to assemble the access plate screws. To establish the safety margin, on your test piece, apply sufficient torque to break the screw(s). This should be a reasonable value above the prevailing torque plus the 12-15 in-lb.

 

[PilotjohnS]

My opinion

My opinion is the actual torque is not critical as long as the screws are not overtorqued and over stressed, because the proseal will glue everything together.

As Vans says, we are building tractors, not spaceships. JMHO

 

[PaulvS]

My opinion is the actual torque is not critical as long as the screws are not overtorqued and over stressed, because the proseal will glue everything together.

As Vans says, we are building tractors, not spaceships. JMHO

Likewise, I just tightened with a calibrated wrist and watched the sealant squeeze out. The screws are going to be wet with sealant, so torque will be difficult to measure accurately anyway.