Liquid teflon or tape?

SSDiv6 · 05-07-2021, 01:46 PM

In the aviation world, the use of Teflon tape is prohibited due to the potential of the tape deteriorating and slivers getting into the fuel, hydraulic or other systems.

Since AN fittings do not seal at the threads, but rather at the flare, mechanically, metal-to-metal, there is no need to use sealant on the flare end.

The only time you need to use sealant is on any fittings with pipe threads. The proper process to use the liquid Teflon sealant is to apply a single bead all around the thread, keeping it away from the first two threads and the end of the fitting. A good indication that just enough sealant has been applied is when a small amount of sealant has been pushed out of the fitting all the way around the threads.

The best fitting sealants that I recommend are Permatex 59235 and Loctite 567. They are fuel, oil and ethanol resistant and great with high pressure plumbing such as brake caliper fittings.

05-07-2021, 01:46 PM	#7
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,043 Likes: 712 Liked 1,577 Times in 581 Posts	Re: Liquid teflon or tape? In the aviation world, the use of Teflon tape is prohibited due to the potential of the tape deteriorating and slivers getting into the fuel, hydraulic or other systems. Since AN fittings do not seal at the threads, but rather at the flare, mechanically, metal-to-metal, there is no need to use sealant on the flare end. The only time you need to use sealant is on any fittings with pipe threads. The proper process to use the liquid Teflon sealant is to apply a single bead all around the thread, keeping it away from the first two threads and the end of the fitting. A good indication that just enough sealant has been applied is when a small amount of sealant has been pushed out of the fitting all the way around the threads. The best fitting sealants that I recommend are Permatex 59235 and Loctite 567. They are fuel, oil and ethanol resistant and great with high pressure plumbing such as brake caliper fittings.