Pipe Tape vs Pipe Dope in High Pressure Hydraulics

[Tractor Seabee]

What Gary said in post #15. :thumbsup:

(btw, Permatex #2 non-hardening.)

IME 1/2" NPT fittings, if Parker need a 2' Johnson bar to tighten leak-free, if TSC (China) need a 4' bar and some will weep anyway. :mur:

Amen, Gary is 100% right this old industrial pipefitter will attest. If a cheater bar is needed you have already distorted the threads and probably the fitting as well. Standard length B/OE wrenches will provide the allowable torque for any thread.

 

[ultrarunner]

Loctite 567 is my go to sealer... keep it on my truck and in the tool room plus thread locker.

 

[LD1]

I use loctite 567 or equivalent PTFE paste /dope, for all NPT threads except hydraulics.

Hydraulics get 545.

NO tape on hydraulics.

 

[Texasmark]

I read where tape is not the recommended solution as it can get into valves and make them leak...foreign object. So I used the goo. I didn't find anything for high pressure apps. locally but did find a blueish gray gummy paste with a dobber in the cap that worked just fine for mine. Can said it was good to like 250# but worked ok for 2500.

 

[downsizingnow48]

For NPT air water fuel (non hydraulic) I use this stuff. No idea what is in it but works fantastic, never had a leak.

 

[DieselBound]

I recently contacted Discount Hydraulics about what sealant to use and this is their response:

Thank you for your inquiry. I have found for me that the teflon tape is easier to work with for NPT fittings. For BSP fittings it depends if its BSPT or BSPP. BSPP ( Parallel) does not need teflon tape because it either seals with an o-ring or with a ball seat on the female. The BSPT (Tapered) you can use the teflon tape on.

 

[LD1]

I recently contacted Discount Hydraulics about what sealant to use and this is their response:

Thank you for your inquiry. I have found for me that the teflon tape is easier to work with for NPT fittings. For BSP fittings it depends if its BSPT or BSPP. BSPP ( Parallel) does not need teflon tape because it either seals with an o-ring or with a ball seat on the female. The BSPT (Tapered) you can use the teflon tape on.

Why take the chance when there is better, and easier to use stuff out there.

I wont say I have never used tape. And wont say that it dont work. Because it does work, and I have used it.

But as others have said, small shreds of tape "can" find their way into the system. Then they like to cause issues with spools, check valves, pilot ports, etc. So if its used, you have to be cautious on how its applied, make sure its all cleaned off if the fitting is ever taken apart and reused, and you have to make sure the tape is applied the correct direction. Where as PTFE dope applied with a brush, or 545 applied from the bottle/tube.....no guess work, no reason to be extra cautious. Just apply and go. Makes life so much simpler.

 

[adventure bob]

Interesting, According to the Parker, the fitting and hose guys:

"•Q: Can Teflon tape be used on hydraulic fittings?
•A: No. Teflon tape may flake. This flaking can contaminate the oil and damage the pump. Warranties are typically voided by using Teflon tape. Use a hydraulic-rated liquid Teflon sealant instead."

 

[LD1]

Interesting, According to the Parker, the fitting and hose guys:

"•Q: Can Teflon tape be used on hydraulic fittings?
•A: No. Teflon tape may flake. This flaking can contaminate the oil and damage the pump. Warranties are typically voided by using Teflon tape. Use a hydraulic-rated liquid Teflon sealant instead."

Spot on.

Too many sources to cite and reference.......but ask this question to ANY big name pump mfg, valve mfg, cylinder mfg, or any other hydraulic component mfg, and the response will be just the same. (Vickers, sun, rexroth, barnes, eaton, prince, etc)

 

[DieselBound]

Interesting... You'd think that a big outfit like Discount Hydraulics would know about all this!

I agree that if you don't do things correctly you can screw stuff up. Lots of folks provide disclaimers to cover their behinds.

Parker doesn't say to avoid tape (they even mention using it):

http://www.parker.com/literature/Tu...imes-Can-I-Reassemble-a-Hydraulic-Fitting.pdf

I would agree with using Loctite 545.