Teflon tape on fuel fittings?

[jpump5]

I've been using teflon tape on pipe fittings (tapered, npt)used in fuel lines of stationary
diesel equipment for years,Now a guy tells me that fuel dissolves the tape
and that I should be using the brush-on teflon pipe sealant.Anyone heard of this?

[DSW]

Yes. The product is made by Gasoila. I've used the both the standard Gasoila and the PLS-2 on all the diesel fuel pumps at the shop I hooked up. It was suggested by the brother in law of my old boss who did fuel system installs for gas stations. We had issues with PTFE tape "weeping" and getting diesel all over the pump and tank in the back of the work truck. Like all pipe dopes, the stuff is messy and hard to clean off stuff when you assemble it, but I haven't seen any signs of weeping on any of the 6 fuel pumps at the shop since we used it.

http://www.gasoila.com/support/seala...enceguide.html

If I get a chance later I'll take a look at the tank in the back of my pickup. It's still got PTFE tape on the joints. I cleaned up most of the diesel fuel the "weeped" when we pulled the tank a few weeks back for maintanence. Not sure if you can tell right now or not what was going on. It's not like diesel was gushing out on things, only that it would get a "film" of diesel over time that would dry and collect dirt, dust and so on and get all over anything that rubed up against it. As soon as I pull the tank to spap bodies on the pickup, I'll be pulling the whole asembly down anyways to fit the new body. At that time I'll redo all the fittings with Gasoila. I think I've got 2 large cans right now, one I bought for us, and one his BIL gave him not realizing I'd already bought a can.

[jpump5]

Never seen Gasoila before.
I like teflon tape for it's convenience/neatness but now wonder if it's causing leaks.
Is Gasoila better than Perma-tex or Rectorseal TEFC pipe dopes for diesel ?

[Black Wolf]

Thanks for the info and the link Doug. I have never heard of this product. I have used Teflon Paste for years on fuel and hydraulic fitting and never had an issue with weeping, but I always keep an eye open for better way to do things.

The issue I usually see is people wrapping the tape on in the wrong direction and it ballz up (Can't fix Stupid) or they use the paste incorrectly and it gets into the system. Also people put too much faith in the old Adage "If a Little is Good, then a LOT must be BETTER"... Such is NOT the case.

Thanks

[Monica]

On my diesel fuel fittings I used the Pera-Tex High Temp thread sealant: http://www.permatex.com/products/Aut...ad_Sealant.htm

[houseoffire]

If you like the ease of using tape there is a company that makes it for aircraft use.
GORE® SKYFLEX® Aircraft Sealant.
I dont know the cost or where to get it.

[Black Wolf]

Originally Posted by Monica

On my diesel fuel fittings I used the Pera-Tex High Temp thread sealant: http://www.permatex.com/products/Aut...ad_Sealant.htm

That is the product that I use as well.

[Renagade]

The Company I Work For Uses Telfon Tape By The Case On Air Line Fittings - The Young People Their Are Like Mr. Black Wolf Said - They Will Use 6" Tape On .25" Fitting - The Few Of Us Old Ones That Are Left Were Trained To Use One And Half Rounds - If It Still Leaks You Have Thread Problems -

But In The Last Year They Have Gone To PST577 Made By Loctite - I Like It Better Than Tape It Has A Quick Seal - We Have Had No Problem With Hydraulic Fluid Or Air Up To 5000 PSI - Just My 2 Cents - Thanks

[jpump5]

I've had to clean pieces of tape out of, or replace devices such as check valves,pressure switches,
transducers, etc. because of someones careless application of teflon tape.
I've even seen where someone completely covered the opening in a pipe nipple.

[DSW]

A couple picts of the pump fittings. I cleaned all of this a few weeks ago when I pulled the cap off the pickup to run down and get the Bobcat I'm buying from Josh. That is not rust in the picts. It's old oil and dirt that collects no matter what I do to try and keep it clean. The stuff gets super hard to clean up after it "dries" for a while. The pump is covered full time by the cap and generally doesn't get "dirty" other than this weeping issue. I don't keep the fuel nozzle in the pump. I've got a separate place I keep it so as not to get diesel all over the back on things if it drips a bit, so that is not the cause of what you see.

Ignore the wire nuts. I was cleaning out the back to try and run down to hook up with Josh tomorrow, and moved them out of the way. Didn't realize where I stuck them when I snapped the pict before moving them back. Usually these are inside a box mounted to the cap along with the light controls for the backup lights for plowing. With the cap off I needed to protect them. Originally the plan was to have the cap back on in two or three days after hooking up with Josh for the machine. Unfortunately that didn't work as planned, and then I had to move fuel for a customer who ran out of home heating oil and was desperate, so I had to hook it back up. It's connected to another switch in the hood as well, so someone can't steal fuel if they get that bright idea.

You can clearly see the extra tape in a few places. I do enough fittings to know how to do tape. Things were good for a while, but then the fittings started to weep. The fittings never look wet, but if you clean them up well, the oil comes back after a few weeks.



Just a general note. I noticed when I pulled up Gasoila's site that none of the dopes were rated for O2 use. I know some companies do make an O2 safe dope, but most "normal" dopes are not O2 compatible. I'll have to look at what the can of "normal" dope I have is. I have a feeling its "Rectum" seal as my buddy the plumber refers to it.

[TozziWelding]

I use Blue Block for just about everything, http://www.herchem.com/Products/thread_sealants.html
I do keep Teflon tape on the truck though, 1.5 wraps plus dope for the stubborn ones. Pipe fittings do wear out, if it goes in to easy, and still leaks no matter how tight you make it, replace it. Pipe fittings are cheap.

[Oldiron2]

Originally Posted by DSW

A couple picts of the pump fittings. I cleaned all of this a few weeks ago when I pulled the cap off the pickup to run down and get the Bobcat I'm buying from Josh. That is not rust in the picts. It's old oil and dirt that collects no matter what I do to try and keep it clean. The stuff gets super hard to clean up after it "dries" for a while. The pump is covered full time by the cap and generally doesn't get "dirty" other than this weeping issue. I don't keep the fuel nozzle in the pump. I've got a separate place I keep it so as not to get diesel all over the back on things if it drips a bit, so that is not the cause of what you see.

Ignore the wire nuts. I was cleaning out the back to try and run down to hook up with Josh tomorrow, and moved them out of the way. Didn't realize where I stuck them when I snapped the pict before moving them back. Usually these are inside a box mounted to the cap along with the light controls for the backup lights for plowing. With the cap off I needed to protect them. Originally the plan was to have the cap back on in two or three days after hooking up with Josh for the machine. Unfortunately that didn't work as planned, and then I had to move fuel for a customer who ran out of home heating oil and was desperate, so I had to hook it back up. It's connected to another switch in the hood as well, so someone can't steal fuel if they get that bright idea.

You can clearly see the extra tape in a few places. I do enough fittings to know how to do tape. Things were good for a while, but then the fittings started to weep. The fittings never look wet, but if you clean them up well, the oil comes back after a few weeks.



Just a general note. I noticed when I pulled up Gasoila's site that none of the dopes were rated for O2 use. I know some companies do make an O2 safe dope, but most "normal" dopes are not O2 compatible. I'll have to look at what the can of "normal" dope I have is. I have a feeling its "Rectum" seal as my buddy the plumber refers to it.

In the right picture, the middle fitting looks cocked WRT the pipe nipple below it. Any chance one was threaded off axis? Maybe that's the cause of the weeping, not the quality of the tape?

As for Teflon tape dissolving in Diesel, I seriously doubt it. Teflon is inert to almost everything and I believe the tape has no 'binders' added that would compromise its integrity. That said, Teflon is a class of compounds, not just one specific formulation, compound or polymer, hence the difference in O2 compatibility, I believe.

[DSW]

I looks that way but it isn't. Optical illusion from the picts.

[Sandy]

I have or had, out in the shop, some teflon tape that is yellowish and on a yellow spool. It states that it is rated for gas or some such statement on there. What "gas" means I'm not sure. Been ages since I've used it for anything.

[Black Wolf]

Originally Posted by Sandy

I have or had, out in the shop, some teflon tape that is yellowish and on a yellow spool. It states that it is rated for gas or some such statement on there. What "gas" means I'm not sure. Been ages since I've used it for anything.

I have one roll of that at the shop too... I can't remember what I ordered it for. I THINK it is approved for use with propane and natural gas.

I guess I'll have a look at it on Tuesday.

Happy New Year!

[DSW]

Most likely for natural gas or Propane.
Example from the site linked above.

http://www.gasoila.com/products/item...apeforgas.html

[Sandy]

Originally Posted by DSW

Most likely for natural gas or Propane.
Example from the site linked above.

http://www.gasoila.com/products/item...apeforgas.html

That's probably it right there. I don't even remember now what year I bought it, do recall it was for a 'gasoline' application and I specifically asked the auto parts for something to use on gasoline. I thought it was interesting they gave me something that said gas and not gasoline.

I have experimented with these things before after seeing some big box store teflon tape turning to slime with gasoline. Doesn't mean that teflon can't be used with gasoline, just means whatever you get at the big box store can't. I definitely don't trust the big box stores to carry products that are what the label says they are and don't buy anything important from them if there is a choice.

Then there is the gasoline blends to deal with. Even diesel now. You may not know exactly what chemicals you are dealing with anymore. I generally try to use nothing if possible.

[slow6i]

Gasoila is OK. We had problems with it with Bio-Diesel before. Not sure if it was a bad batch, or if the Rep we were dealing with gave us the wrong stuff, but ive tried to stay away from them because of that.

My favorite lately, is the Rectorseal TrueBlu. Compatible with alot of stuff. NOT FOR OXYGEN. They say its also vibration proof... I have yet to test this though.

(http://www.rectorseal.com/files/214/dstrublu.htm)

I also like that Megaloc stuff that Tozzi posted.

[76GMC1500]

The trouble with Teflon tape is that it leaves strings behind that tend to plug things up if you ever have to disassemble a fitting.

I don't understand why nobody knows they exist but anaerobic sealants are the best. Teflon and dopes are good if may need to reposition fittings after assembly but anaerobics make the tightest seal. Look into Loctite 515 for pipe thread and Loctite 545

The best part about the anaerobics is that they will not cure except for between the threads. This means any excess that gets extruded out will remain a liquid or a gel so it won't plug up sensitive systems.

Finally, they don't cure in the tube. I hate reaching into my tool bag for a tube of RTV only to find it already vulcanized. The anaerobic sealants are always ready to go and will never let you down.

[ASE_MasterTech]

No teflon sealant (tape or otherwise) permitted on brake fittings is the rule in automotive applications.
Otherwise...
We use Permatex teflon dope (rated for motor fuels) available from any NAPA store on the 100+ diesel & gasoline 'pump-hose-nozzle-etc' fittings we have.
Never had a problem...

[Stick-man]

The yellow tape you buy from the home stores are used for nat gas/propane. I have never used it for anything else, so I can't help you there.

DSW, how has that GPI meter held up? Would you go with it again?

[DSW]

Originally Posted by Stick-man

DSW, how has that GPI meter held up? Would you go with it again?

I've been very happy with them.

That's my 2nd one on that tank. The 1st one finally died after 11 years last summer. My fault really. It still had the original batteries in it and when it finally died the batteries had leaked ( still functioned up to the last day) and had messed up the insides. Never seen batteries leak before the batteries died before. I went straight out and bought an identical replacement and would have no issues doing it again. I also have one on the fuel pump at the shop that's about 4 or 5 years old with no issues. The tank at the house has one of the big GPI analog meters on it. I would have liked one like that for the tank at the shop, but the cost was significantly higher and I didn't see a reason to justify the added cost.

[rlitman]

Teflon tape is color coded by most manufacturers.
White is the thinnest, and is made from a low density teflon (BTW, white teflon tape isn't made for connections over 3/8"). Blue (if you can find it) is also low density, but is thicker. Personally, I never use either of these.
Pink is a thick and is made from a high density teflon designed for water lines (my favorite for plumbing, but I still prefer Rectorseal dope over tape). Technically "red", this tape is required for water lines over 3/8", up to 2".
Yellow is designed for propane and natural gas lines, but I ALWAYS use pipe dope for this (and inspectors around here are known to fail a job if tape is seen on a gas line).

Still, I've used Rectorseal on fuel oil connections, and haven't had any weeping from it. That's what I'd choose first for any permanent joint.

If you really want to use tape on diesel lines, I'd use the pink or yellow.

[ShortbusWelder]

Originally Posted by TozziWelding

I use Blue Block for just about everything, http://www.herchem.com/Products/thread_sealants.html
I do keep Teflon tape on the truck though, 1.5 wraps plus dope for the stubborn ones. Pipe fittings do wear out, if it goes in to easy, and still leaks no matter how tight you make it, replace it. Pipe fittings are cheap.

I use Blue Block as well, works very good, just don't get any on you.

I also use Blue Monster teflon tape as well, it works good.

Depending on what I'm doing, I usually dope, tape, then dope, this is on the larger size pipes, mostly when I'm installing boilers.

[TozziWelding]

For steam work, I dope, tape, then never seez. Nothing worse than straight dope on steam lines after they have been in service for years. I like that blue monster tape too.