DJE
Well-known member
Can I use PTFE tape to seal threaded joints on diesel pipes? Or do I need something special?
I haven't dismantled the old ones yet but I don't think they have olives. These are the connections to the fuel tank and shut-off valves. They look like threaded elbows, ball valves, and hose tails. They connect to what look like threaded fittings on the top of the tank and flexible hoses that lead to the engine. A couple of the joints are a bit loose.
I'm not sure what type of connection we're talking about.
If they are tapered fittings then PTFE or a sealant will be required. If they are compression fittings with an olive or a flared end or a washer or an O-ring, then no PTFE or sealant should be required.
Richard
They are threaded fittings, not sure if they are parallel of tapered threads, but currently sealed with a mixture of PTFE tape and some sort of fibrous cord. And loose enough to rotate with one finger so I'm surprised that they aren't letting in a lot of air.
PTFE on threaded pipe is fine for Diesel - be carefully applying it so as not to go over the end of the pipe.
Do not use PTFE or any other jointing compound on olive fittings.
PTFE info here:-
https://www.calpaclab.com/teflon-ptfe-compatibility/