AN fittings & Teflon Tape
- Thread starter Aeroking
- Start date
cloneman315
Active member
Re: AN fittings & Teflon Tape
pipe sealant?
pipe sealant?
Last edited:
JSM
Active member
Re: AN fittings & Teflon Tape
AN stands for Army Navy just a side note.
The sealing is done on the flare section, not on the threads at all. No sealant is advised or needed. Putting sealant on the threads does nothing as it isn't sealing there anyways.
The only threads that need sealant are NPT (National Pipe Threads) which are tapered.
This picture shows where the sealing surface is. It has been painted to demonstrate proper sealing.
Here is a fitting with both an AN on one end and NPT on the other.
And just a NPT, you can see the taper if you look. Easier to see when you have one in your hand.
Also most might not know there is also another AN fitting called a Straight AN fitting.
These threads are straight (not tapered like the NPT) but have an O-ring to seal. These also do NOT require sealant as again the o-ring is sealing not the threads.
Tech Tip: If you ever have to tap an NPT do NOT run the tap all the way down like you would a normal tap. Some say it should be 12 turns in, I find it best to just tap some and check with the fitting I plan to use. You should have around 75% engagement when done.
AN stands for Army Navy just a side note.
The sealing is done on the flare section, not on the threads at all. No sealant is advised or needed. Putting sealant on the threads does nothing as it isn't sealing there anyways.
The only threads that need sealant are NPT (National Pipe Threads) which are tapered.
This picture shows where the sealing surface is. It has been painted to demonstrate proper sealing.
Here is a fitting with both an AN on one end and NPT on the other.
And just a NPT, you can see the taper if you look. Easier to see when you have one in your hand.
Also most might not know there is also another AN fitting called a Straight AN fitting.
These threads are straight (not tapered like the NPT) but have an O-ring to seal. These also do NOT require sealant as again the o-ring is sealing not the threads.
Tech Tip: If you ever have to tap an NPT do NOT run the tap all the way down like you would a normal tap. Some say it should be 12 turns in, I find it best to just tap some and check with the fitting I plan to use. You should have around 75% engagement when done.
Don W.
Stab it and steer it
Re: AN fittings & Teflon Tape
As explained, not needed on flare fittings. Now my :2cents: is never use teflon tape. It can cut and the little piece will end up in your system. It's so darn slippery the fitting will not stay tight. Use a thin coat of commercial grade pipe dope. I know, most will have some teflon in it but it's not the same. Paint on a thin coat on the (tapered) male pipe thread only. When installing the hose use two wrenches, one to turn the hose fitting one to hold the pipe fitting. This to keep the pipe fitting from turning and forming a leak. Unlikely but possible.
As explained, not needed on flare fittings. Now my :2cents: is never use teflon tape. It can cut and the little piece will end up in your system. It's so darn slippery the fitting will not stay tight. Use a thin coat of commercial grade pipe dope. I know, most will have some teflon in it but it's not the same. Paint on a thin coat on the (tapered) male pipe thread only. When installing the hose use two wrenches, one to turn the hose fitting one to hold the pipe fitting. This to keep the pipe fitting from turning and forming a leak. Unlikely but possible.