rayclar
Silver Member
When installing hydraulic fittings with one end pipe thread should i use tee tape there or just use the fitting bare?
pipe thread?
- Thread starter rayclar
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Egon
Epic Contributor
Maybe use pipe dope. :thumbsup:
Bare threads ain't the best.
Bare threads ain't the best.
deereman75
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I use teflon tape for all tose sort of things, air lines, water lines, ect..
Sockwell
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Loctite makes a sealant for use with NPT threads in hydraulic systems. We use it in plant maintenane w/o leaks.
J_J
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I would recommend using a sealant/lubricant on all NPT pipe fittings.
Soundguy
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i like gasoila... I HATE tape.
tape threads block small prts when it shreds.. and solvents won't remove shreded tef tape inside small valves...
soundguy
tape threads block small prts when it shreds.. and solvents won't remove shreded tef tape inside small valves...
soundguy
Shield Arc
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Years ago I learned from a heavy equipment master mechanic to use the black Permatex gasket sealant on hydraulic fittings. He also said never use teflon tape, excellent way to take out a pump!
Gary Fowler
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I like the heavy white teflon paste. Excellent lubricant and thread sealer without the possibility of shredded teflon getting into your system later. That said, properly applied T tape will not harm your system on initial installation. Where you get the problem is when you have to remove a connection that has had tape in the threads. It is almost impossible to get all of the tape out of the female connection without some special brushes. Avoid all that with the paste. A bit messy but just as effective.
Scooby074
Super Member
Loctite 592 PST.
Tape SHOULDNT be used, especially on any of the pressure or supply lines...
HOWEVER, lately ive been seeing major issues with chinese sched 40 pipe and fittings being basically crap, and leaking like a sieve no matter what dope was used or tightness achieved.
A trick i learned from an old timer was to smear dope on the threads first, then a wrap or 2 of tape 2-4 threads back from the opening (so you dont contaminate the fluid), then cover that with a layer of dope. You WONT have any leaks after this, even on poorly made fittings. But you muat take extreme care to keep the tape well back from the opening, especially on supply lines to the pump.
Another oldtimers trick was to wrap the threads of the pipe in silk thread along with dope. I havent done the latter, but have had great luck with the above trick on problematic fittings.
Tape SHOULDNT be used, especially on any of the pressure or supply lines...
HOWEVER, lately ive been seeing major issues with chinese sched 40 pipe and fittings being basically crap, and leaking like a sieve no matter what dope was used or tightness achieved.
A trick i learned from an old timer was to smear dope on the threads first, then a wrap or 2 of tape 2-4 threads back from the opening (so you dont contaminate the fluid), then cover that with a layer of dope. You WONT have any leaks after this, even on poorly made fittings. But you muat take extreme care to keep the tape well back from the opening, especially on supply lines to the pump.
Another oldtimers trick was to wrap the threads of the pipe in silk thread along with dope. I havent done the latter, but have had great luck with the above trick on problematic fittings.
moored4
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If your breaking fittings cause of 'too much tape' then I would suspect the fitting is not a Hydraulic fitting but just regular pipe! Make sure the system is all rated for the pressure it will see under load! :thumbsup:
Last edited:
troutsqueezer
Veteran Member
I don't use anything, works for me. I just clean the threads. There is usually some hydraulic fluid you can dip your finger into and wipe it on the threads which helps lubricate the fitting.
Deere Dude
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X2
If I put a pipe fitting fitting together and I want it to leak, I'll use tape.
If I want to be able to take it apart again to fix a slow leak, I'll use paste.
If I don't want it to leak, I'll use Locktite.
But, anything is better than nothing.
5030
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Not me.
A person needs to ascertain what type of thread it is prior to assembly.
If it's NPT dryseal, no additional sealant is needed or warranted.
Never use teflon tape on HP hydraulic fittings where there is a chance the tape could get in the flow to the pump prior to the filter. Teflon tape and HP pumps don't mix well.
Ues a proprietary sealant like Permatex or a made for hydraulic fitting sealant. Many are available at the hardware store.
NPT threads are designed to lock together to form not only a mechanically superior joint, but for the most part a fluid tight one as well. That's why they are tapered.
J_J
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I am amazed at some of the post about sealing NPT threads.
No sealant at all, not good, you need more than metal to metal contact.
There have been standards for a good many years for sealing pipe threads, and some of those have been mentioned above.
No sealant at all, not good, you need more than metal to metal contact.
There have been standards for a good many years for sealing pipe threads, and some of those have been mentioned above.
5030
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No sealant at all, not good, you need more than metal to metal contact
Absolutely false, depending on the type of thread (as I stated above) and the location of the fitting as it pertains the not only the fluid type but post-pre- filtering capabilities.
By the way, I have a high pressure operators license, do you? Go look up the ASTM specifications as they pertain to pipe joints when physically joined by corresponding threaded components, compatible sealants (if necessary) and their impact on various fluids.
I will say the most over the counter fittings are not dryseal but to make a blanket statement that sealant is required is false.
Absolutely false, depending on the type of thread (as I stated above) and the location of the fitting as it pertains the not only the fluid type but post-pre- filtering capabilities.
By the way, I have a high pressure operators license, do you? Go look up the ASTM specifications as they pertain to pipe joints when physically joined by corresponding threaded components, compatible sealants (if necessary) and their impact on various fluids.
I will say the most over the counter fittings are not dryseal but to make a blanket statement that sealant is required is false.
High Compression
Platinum Member
I depends on the fitting. If it is a flare fitting, then you should leave it bare. Tighten to snug, then turn one flat spot more. (1/6 of a turn) If you over tighten flare fittings they will crack.
If it is a pipe thread fitting, no flare, npt, metric, British, or imperial, then I recommend pipe dope rated for petroleum. I have used tape, and it tends to start leaking after a while.
955Lincoln
Gold Member
Some of your information is good and some not so good. The OP asked a simple question about sealing so why mention a fitting (NPTF Dryseal) that there is a 99.99% chance he doesn't have? Or mention it for his knowledge and move on to what he probably has and include your thoughts on sealing.
NPT threads are not expected to seal dry and need a sealant.
Mace Canute
Elite Member
X 2! I don't know how many times the distinction between NPT and NPTF has been made in previous threads but apparently it hasn't been enough!
LD1
Epic Contributor
Another vote for the PTFE paste. (the white thick stuff).
EVEN on the NPTF I use it. IT doesnt hurt anything. And those seal by thread deformation. So If you have to remove and reassemble, sealant will probabally be the only thing that will keep it from leaking.
The only pipe thread that doesnt get sealant on what I work on, is NPSM fittings. These are where there is a cone (kinda reversed of a JIC flare) inside the swivel and it seals against the inside of the pipe, NOT the threads. Very similar to how a flare seals.
EVEN on the NPTF I use it. IT doesnt hurt anything. And those seal by thread deformation. So If you have to remove and reassemble, sealant will probabally be the only thing that will keep it from leaking.
The only pipe thread that doesnt get sealant on what I work on, is NPSM fittings. These are where there is a cone (kinda reversed of a JIC flare) inside the swivel and it seals against the inside of the pipe, NOT the threads. Very similar to how a flare seals.
