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.

 

[/pine]

FWIW...Teflon is a lubricant not a sealant...it works on most pipe threads because they are NPT and the lubricant helps the taper seal easier...

 

[SylvainG]

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

Thanks all. I think I'll go with Permatex 565 available at CanadianTire.

Hmm, the 3" extension is actually black iron. I couldn't get it in the hydraulic section. That pipe will sit between the filter head and the tank, meaning it will only see atmospheric pressure no hydraulic pressure. Is that still an issue?

 

[WranglerX]

Personally almost any style of paste sealer should work as long as the specs are for "oils" and "high pressure" uses.... As motioned above read the application parameters/specification on back of can or tube to see if it is applicable to what you are trying to do...

I found this product at local hardware store and use it on steel (NPT) and plastic pipe threads (PVC) and fuel and house plumbing, it really seems to be a one product fits all applications...

You may not be able to find this particular brand, but look at specs on back of tube for examples of application...

Did mention I hate PTFE tapes as it always seem to plug something up no matter how careful I am applying it...

Dale

 

[3Ts]

I had problems with sealing one NPT fitting. I tried lots of stuff including the blue paste which my hydraulic shop recommended, but still had leaks. The 545 was recommended to me by members on this forum. I looked all over for it and couldn't find it, ended up ordering it from Amazon. Kinda expensive, but it works really well!

 

[Michael In Tennessee]

Thanks all. I think I'll go with Permatex 565 available at CanadianTire.

Hmm, the 3" extension is actually black iron. I couldn't get it in the hydraulic section. That pipe will sit between the filter head and the tank, meaning it will only see atmospheric pressure no hydraulic pressure. Is that still an issue?

That requires an activator. Make sure to buy it. The stuff I suggested doesn't.

 

[LD1]

Thanks all. I think I'll go with Permatex 565 available at CanadianTire.

Hmm, the 3" extension is actually black iron. I couldn't get it in the hydraulic section. That pipe will sit between the filter head and the tank, meaning it will only see atmospheric pressure no hydraulic pressure. Is that still an issue?

There is no issue with black iron on the low pressure return on suction side of hydraulics. Just don't use them on the high pressure side

 

[PILOON]

Lacking thread seal, other than Teflon tape, I tried some urathane construction caulking as a thread seal.
It has worked very well 4 me. Lubricates and sets up solid making an excellent seal.

Also I have noticed that many offshore products seem to use epoxy to seal hydraulic and air fittings. Heat is my 'go to' whenever I need to crack them apart.

Whenever I apply a sealant I always apply it to the male component starting a couple of threads back so as to not introduce any into the flow, be it air or hydraulic .
So far never a problem.