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Polypropylene (Banjo) fitting retention

5K views 18 replies 13 participants last post by  brownie31 
#1 ·
Does anyone have any Indian tricks or a non permanent product that helps keep these tight/from leaking after use/vibration. I’ve tried several different tapes and then the liquid Teflon stuff and the glue stick form. Thanks.
 
#6 ·
If it’s the gasket you’re talking about, I just received some extra thick gaskets from polywest, after I phoned to complain about leaking fittings, both on 3” inlet and outlet on my new 3. The new gaskets helped to slowed down to slow drip. Polywest said to use banjo cam locks because they have closer tolerances. I had bought new cam locks fittings, were from the states, but maybe they were imported from China with American stickers.

the thick gaskets are the ticket for the cam locks.... now my problem is the threaded connections. The unit is a tank mounted on a chassis with a centrifugal pump, 1” sprinkler gun, and a chemical educator for fertligating some vegetable crops. Not being an off the shelf setup it’s mainly 2” npt threaded connections except the fill port


If you are talking the threaded connections are leaking, they sell a blue vibration resistant joint seal just for this use. Think it is made by rectorseal.


I am thinking Lexionman is talking about the threaded connections on the polypropylene fittings on the Chem Handler. Yes mine leaked and dripped too and I never could get them to totally stop. What about a marine quality sealer like Sika Flex or another one by 3M is 4200 or 5200 although 5200 gets pretty permanent. All of these stay rubbery and are the go to sealers in the boat world for almost anything. Although I have never used them on threaded fittings it might be worth a try because of the water proof nature and the flexibility.
Twix I will check that out, and transaxial you’re right the just drip enough to aggravating. They don’t rotate/loosen but start dripping and if you turn to try and tighten the leak gets worse. I never thought about a marine product, but surely they have to maintain watertight integrity in plumbing for bilges and such. I hate to spend a couple grand to re-plumb it if something simple does the trick. Thanks guys.
 
#4 ·
If it’s the gasket you’re talking about, I just received some extra thick gaskets from polywest, after I phoned to complain about leaking fittings, both on 3” inlet and outlet on my new chemhandler 3. The new gaskets helped to slowed down to slow drip. Polywest said to use banjo cam locks because they have closer tolerances. I had bought new cam locks fittings, were from the states, but maybe they were imported from China with American stickers.
 
#5 ·
I am thinking Lexionman is talking about the threaded connections on the polypropylene fittings on the Chem Handler. Yes mine leaked and dripped too and I never could get them to totally stop. What about a marine quality sealer like Sika Flex or another one by 3M is 4200 or 5200 although 5200 gets pretty permanent. All of these stay rubbery and are the go to sealers in the boat world for almost anything. Although I have never used them on threaded fittings it might be worth a try because of the water proof nature and the flexibility.
 
#7 · (Edited)
At one time we built plenty of equipment for applying and storing phosphoric acid and always used RTV silicone. It’s nicer on a thread that has never had another product on it but even then the old product can usually be polished out of the threads with a wire brush, although that can be challenging on small sized female threads. You need to be careful not to over torque things when assembling because the RTV is an exceptional lubricant before curing.

When a cam coupling starts leaking at the gasket you can insert a large zip tie through the openings around each cam before you couple it to make it compress the gasket more. It was a common issue when transferring acid when one fitting was fixed in place and a hose stand wasn’t available because of the extreme weight of the acid in the hose, something like 16 or 17 lbs per imp gallon I believe.
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#8 ·
silicone glue or I prefer rector seal brand. And ya, the blue stuff works good I would like to know what I see on a few machines from factory that is kinda blue/green and gets hard. That seems to work great. And it comes off when you need to take it apart. I have used anaerobic gasket maker for stubborn pipe thread leaks. It seems to always work but you may never get it apart again. Used to use it when adding on thumb attachments on CAT excavators years ago. Had to take one fitting apart. Took two guys and a couple long cheater bars to break it free. I don't use it unless I need to.
 
#9 ·
I tried following Banjo rec by using the blue stuff before. I thought I got a premium Oatey product, but it was terrible. Maybe it was a bad batch? Used the good quality Teflon tape in the orange case for the rest of the project... it is holding up very well on the water tender/chem handler build.
 
#11 ·
I have experienced similar problems with threads leaking. Have been having good luck by applying a small amount of rectorseal tru blu then wrapping on some thread tape and then coating both the male and female threads with the tru blu and then assembling and wiping off any excess goop.
I think the putting the sealant on the female thread and making sure it is applied into the threads all the way around is the trick to getting a good seal. Especially on the 1.5 inch and larger.
 
#17 ·
Lookup PLS2, store by the house is getting a new diesel pump and that’s what they were using on the plumbing. I’m sure that stuff has to be pretty good to pass all their regulations. With all these good suggestions and brands I hadn’t heard of So far I’ve found everything from fuel pump chemicals to boat sealants. If I could just find what they use to seal up the crappers pipes on an A380 airbus I think I’d be leak free for life.
 
#19 ·
We have tried almost everything, the best I have found is a couple wraps of Teflon tape(pink or yellow, not white) then just regular clear, window silicone. Let it set up for a day and it seems to be good.
 
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