Help on which thread sealant should I use

[SylvainG]

Hi, Princess Auto sales these two type of thread sealants:

Thread Sealant with PTFE
High-Temperature Thread Sealant

I'm trying to seal the fittings of a hydraulic pressure gauge I made as well as the fittings of a return to tank filter for my log splitter (didn't come with one so I'm adding it). Which of the two do you think I should get?

Lots of fittings on the log splitter filter to seal: Existing 1" hose fitting, 1" female to 3/4" male reducer. 3/4" 10gpm filter head, 3/4" male to 3/4" female elbow, 3/4" 3" extension (tank port is at the bottom of the tank and I want to raise the filter head so the filter isn't lower than the tank, hence this extension and elbows), 3/4" female to 3/4" male elbow, 3/4" female to 1" male 'adapter', 1" tank inlet.

Thanks.

 

[revver6]

Loctite 545 is all I use on hyd fittings

 

[Seven Gables]

I use the PTFE sealant on all hyd threads, works excellent

 

[LD1]

Loctite 545.

But you only need sealant on NPT threads. Dont use any sealer on ORB, JIC, or ORFS.

If you use NPT fittings....get steel hydraulic fittings. No black iron or galvanized water pipe fittings

 

[Seven Gables]

True , I should of said all hyd fittings that need sealant

 

[TractorGuy]

For pipe thread fittings on oil or gas I use aviation permatex.

 

[ericm979]

NPT is fine for 60 psi water lines but it's not made for high pressure hydraulics. I've tried teflon tape and teflon pipe dope. Neither seals well. Locktite 545 works so much better. At 2000+ PSI the teflon is not a sealant, it's just a lubricant for the threads. The 545 is a sealant. I stopped having to retighten high pressure NPT fittings when I started using it.

 

[/pine]

I think the problems with NPT fittings not wanting to seal is the fact that they are not intended to be used (tightened to torque) more than once...it is the taper that creates the seal as the threads are tightened...

 

[Michael In Tennessee]

Permatex Pneumatic/Hydraulic Sealant.​

Probably the same as the locktite product. Works way better than Teflon sealant.

 

[Captain Dirty]

Read the fine print. What you want is a SEALANT which is probably in large print on the package. The fine print will will tell the application--air, hydraulic, steam, etc.--and often exclude things like corrosives. I like to see "pressure tested to over 10,000 psi". The temperature range is unlikely to be a problem except for application at cold (like 0°F and below) temps. The fine print will include instructions and often note a curing time.

All that said, I use Locktite 545 or Chesterton No. 900 Gold End.