Sealing fittings on FASS/Preporator systems

[Dkevdog]

I was curious to know what other are using to seal the threads on pipe fittings used in either of these two (or other) systems. I have had a small leak from a fitting that I am fairly certain is poorly machined fitting, but because the issues of using the correct material to seal threads has been debated, I thought I would ask again.



I know that diesel by its viscosity nature is difficult to contain and keep from evetually weeping through.



Kev

 

[BigDaddy]

I have had very good luck with Leak Lock.



I was first introduced to this sealant ten years ago when I was replacing my Heating Oil Tank and I have been using it ever since for a number of thread sealing applications.



You should be able to find it at any plumbing supply shop.



Joe

 

[Dkevdog]

Joe- Have you used this on Diesel applications?? Does it cure or setup to a semi-hard or hard? It says flexible, so I assume that means that it semi-hard.



Thanks, I'll check into it further. Any others?

 

[BigDaddy]

I use the blue and when dry, it is HARD



Perhaps the yellow (with Teflon) is semi-hard



Yes, I have used the blue on a post fuel filter fuel pressure sender and it never leaked again

 

[HoleshotHolset]

home heating oil = diesel fuel

Kev: #2 home heating oil is pretty much the same thing as diesel fuel... it's dyed and has more crud in it, but that's about it. I know someone who has been running it in his truck since he bought it and never had any problems.



How about this stuff?: #ad




Pipetite® Paste Pipe Thread Compound



* Soft set pipe thread compound

* For refrigerants, butane, gasoline, oil, as well as water, steam, air, natural gas and LP gas.

* Use on metal threads.

* Classified by Underwriters Laboratories, U. S. A. and Canada.

* Do not use on Oxygen service, use PTFE Tape or Oxytite®.

* Sealing temperature: up to 400°F (204°C).

* Pressures: to 5,000 PSI (340 BAR) for liquids to 2,600 PSI (177 BAR) for gases.



Above info taken from this website...



Matt

 

[PRout]

I used Permatex #2 on all fittings. Have been told to avoid teflon tape in diesel applications, because diesel will eat it.



Also, have read that the large fuel filter on the FASS can leak, and I have re-tightened mine twice now, and just noticed that it is still weeping fuel, so im sure there is some air entering the system there.

 

[Dkevdog]

Originally posted by Shortshift

I used Permatex #2 on all fittings. Have been told to avoid teflon tape in diesel applications, because diesel will eat it.

Been told the same thing, although many members are using Teflon tape on their isolators and senders. Interestingly, I have a science experiment going, I have several pieces of different types of Teflon tape in a jar of #2. Been there a few days now, but we'll see. There are teflon tapes made for petrochemical applications, too.



I'm going to give the Leak-Lock a try, local Graingers had it sitting on the shelf ready to go.



Kev

 

[JohnE]

Tape is not recommended as it tends to break loose and get in the works when you assemble and disassemble. If you assemble and leave it, fine.

Teflon paste or PST is recomended for pipe fittings, BUT you must keep it back a few threads from the end of the fitting same as tape. Paste or tape, teflon is really hard on pump type parts.



I use PST on air intake horn bolts to reseal. In fact the red seal on the bolts is Vibra-seal from Loctite and PST is the recommended re-application.



Leak lock sounds really good. Even applicable to plastic pipe which is a no-no for PST.

 

[Dkevdog]

Teflon tape might come apart when you disassemble fittings, but all you have to do is take to clean it out. Either way, Diesel doesn't seem to have any effect on my experiement. I have used two different loc-tite products and niether seems to dissolve in diesel fuel, nor doesany of the three teflon tapes. I have tried loctite Pipe thread sealant, (black goo) and the white teflon paste, as well as white, yellow and gray teflon tapes. None seem to deteriorate in diesl fuel after a couple days. The black loctite even cured and got semi hard whil submerged in #2 just as it is supposed to. This really makes me thing that I have a poorly machined fitting. (What do you expect from chinese imported pipe fittings?) Because I have to dissasemble it anyway to get the bad fitting out, I will use the leak-lock on re-assembly. If nothing else, I've learned a few things. I guess long term soaking in the #2 will be the real test, I have no intentions on taking the stuff out, so I can see the results as time passes.



Kev

 

[BigDaddy]

Originally posted by Dkevdog

I'm going to give the Leak-Lock a try, local Graingers had it sitting on the shelf ready to go.



Kev

Try it, you will like it

Originally posted by Dkevdog

Teflon tape might come apart when you disassemble fittings, but all you have to do is take to clean it out. Either way, Diesel doesn't seem to have any effect on my experiement. I have used two different loc-tite products and niether seems to dissolve in diesel fuel, nor doesany of the three teflon tapes. I have tried loctite Pipe thread sealant, (black goo) and the white teflon paste, as well as white, yellow and gray teflon tapes. None seem to deteriorate in diesl fuel after a couple days. The black loctite even cured and got semi hard whil submerged in #2 just as it is supposed to. This really makes me thing that I have a poorly machined fitting. (What do you expect from chinese imported pipe fittings?) Because I have to dissasemble it anyway to get the bad fitting out, I will use the leak-lock on re-assembly. If nothing else, I've learned a few things. I guess long term soaking in the #2 will be the real test, I have no intentions on taking the stuff out, so I can see the results as time passes. Kev

We have used a variety of loctite sealants and adhesives with Jet A & B throughout the years and during short term applications, Loctite products hold up very well. However, we have found that after an extended period 2 - 3 years Loctite becomes very brittle and very susceptible to vibration.

 

[pgleavitt]

Hey Kev, Try this stuff. It's called Gasoila and I found it at a Petroleum supplier. The kind of place that sells bulk fuels,oils and such. It's the same stuff they use to put high pressure,high flow pumps and nozzels together at card lock fuel places. I have used it to put transfer pumps together. It's insoluble to gas,diesel,kerosene ect. and works great. Made by Federal Process Corp. in Cleveland,OH. It's like teflone paste only better. If you can't find it,PM me and I will hook ya up.



Pete

 

[Dkevdog]

Gasoila and leak lock sound very similar, althought I thin I was told that the Gasoila is fairly permanent. Graingers also had the Gasoila but the guy recommended the leaklok over it. I disassembled the fittings and put the leaklok on all of them, and will let them dry overnight. It seemed like a good sealant. We'll know tomorrow ... .





Kev

 

[Murle]

Been using teflon tape on all fittings on my tractors and trucks for 20 years... . never had a leak and have never had diesel eat the teflon.

 

[lmills]

I am not sure how you guys got so lucky with teflon. I must be one of the guys with the bad luck. Mine leaked from day one. They were the first fittings I ever had that leaked when teflon tape was used. I ended up switching over to permatex #2

 

[Dkevdog]

I too have used teflon tape on fittings, but I wanted a better seal on this system since they were larger lines than the 1/8" I had used teflon on in the past. Diesel will not dissolve teflon tape, but it will absorb into the material and can weep past it. It largely depends on the fitting and whether they are tapered, as well as how well the Chinese machined the fitting. I'm not saying Teflon won't work, I'm just saying there are better sealants out there.



Kev

 

[Murle]

Well If it don't leak I cannot see how there could be better. I have never had a leak. And I have used 100's of rolls of teflon tape.

 

[lmills]

yours didnt leak, mine did, so there must be better

 

[Dkevdog]

Originally posted by Murle

Well If it don't leak I cannot see how there could be better. I have never had a leak. And I have used 100's of rolls of teflon tape.

Well when you use 100's of rolls... ... ... . my goodness it must be gospel!! My apologies! Let me ask you this then, why doesn't the petrochemical industry seem to use it?? The place that reccommended leak-lock and gasoila did not even mention teflon tape- although they did carry a special type of heavy tape.



You use what you'd like. You know what they say, to each his own.



I was pretty impressed with Leak lock, and have no leaks or worries of tiny shards of teflon plugging injectors.





Kev

 

[Murle]

Originally posted by Dkevdog

Well when you use 100's of rolls... ... ... . my goodness it must be gospel!! My apologies! Let me ask you this then, why doesn't the petrochemical industry seem to use it?? The place that reccommended leak-lock and gasoila did not even mention teflon tape- although they did carry a special type of heavy tape.



You use what you'd like. You know what they say, to each his own.



I was pretty impressed with Leak lock, and have no leaks or worries of tiny shards of teflon plugging injectors.





Kev

My goodness since you have had no leaks with Leak Lock it must be gospel. Get off of it Dkevdog... . It is starting to smell different.

 

[Dkevdog]

Murle, until I use 100's of bottles of Leak Lock, I couldn't possibly be the preacher .

Get off of it Dkevdog... . It is starting to smell different.

There's only one thing that could be causing that... .