Thread tape, thread sealant, or ????

[Elliott in GA]

Use a little common sense. Household plumbing and field sprayers do not crash and kill people.

Dan

Well, what if it was the plumbing in the airplane's lavatory, or it was an Ag spray plane?

 

[Sidekick]

I recently did battle with some china pipe threads and found the Blue Monster thread sealer to be the solution for me. I also had to chase the the threads both male and female. Some the tap and die went in and on smooth and some took a couple turns near the end to straighten.

View attachment 170043

I used Aviation Permatex on gas and oil fittings for years with no leaks. It was no match for the inferior pipe thread fittings I encountered on my last project.

I also add lamp wick to Chinese pipe threads.

 

[GeoHorn]

My boom sprayer has some form of paste sealant on all the pipe fittings. It doesn't take much to plug up the nozzles given how fine the tips are, so I'd use some kind of PTFE paste sealant rather than tape. I ordered the stuff shown below (will be here tomorrow) for the BSPP/NPTF to Summit Hydraulic 1/2" Ag couplers.

View attachment 170044

That reminds me of the motor oil additive which claimed to have PTFE in it to ”improve“ lubrication.
One of the oil analysis labs showed that only a few minutes of circulation thru a quality oil filter quickly removed it.

I wonder,…. if your sprayer nozzles are so fine as to easily clog…. if PTFE wouldn’t pose a problem.

(Teflon actually has limited and specific application. I suspect in pipe-thread-paste it’s purpose is more to reduce friction installing the fitting, thereby providing a tighter fitment…. rather than any sealing function of the teflon itself.)

 

[McMXi]

That reminds me of the motor oil additive which claimed to have PTFE in it to ”improve“ lubrication.
One of the oil analysis labs showed that only a few minutes of circulation thru a quality oil filter quickly removed it.

I wonder,…. if your sprayer nozzles are so fine as to easily clog…. if PTFE wouldn’t pose a problem.

(Teflon actually has limited and specific application. I suspect in pipe-thread-paste it’s purpose is more to reduce friction installing the fitting, thereby providing a tighter fitment…. rather than any sealing function of the teflon itself.)

That's exactly what PTFE tape or paste is for ..... to reduce friction so that the built in sealing ability of pipe threads work as they should.

 

[JohnDB]

I ordered the stuff shown below (will be here tomorrow) for the BSPP/NPTF to Summit Hydraulic 1/2" Ag couplers.

I'll be interested to hear how it works out. Which parts are BSP and which are NPT? Same tpi, but different thread forms I thought were not reliable for leak tightness, even with doping, in hydraulic pressure situations.

 

[hagrid]

Use a little common sense. Household plumbing and field sprayers do not crash and kill people.

Dan

Depends on how much effort you put into the endeavor.

 

[TheOldHokie]

PTFE is a solid at temps under 320C.

PTFE "thread paste" is a conventional pipe dope that contains PTFE fibers that act as a gap filler and lubricant.

Its just "ground up tape" in a carrier.

Dan

 

[McMXi]

I'll be interested to hear how it works out. Which parts are BSP and which are NPT? Same tpi, but different thread forms I thought were not reliable for leak tightness, even with doping, in hydraulic pressure situations.

The male 3/8 BSPP end of the adapter threads into the valve bodies at the rear of the tractor. The other male end of the adapter is 1/2" NPTF which threads into the female 1/2" NPT thread at the base of the 1/2" Ag coupler. I'm only using the PTFE paste for the NPT connections. The BSPP uses o-rings.

 

[TheOldHokie]

I'll be interested to hear how it works out. Which parts are BSP and which are NPT? Same tpi, but different thread forms I thought were not reliable for leak tightness, even with doping, in hydraulic pressure situations.

Hydraulic fittings use the NPTF thread form which is designed to seal pressure tight without sealant. Also known as Dryseal pipe threads. In practice sealants are often used eith NPTF fittings and they are good to several thousand PSI. Their main disadvantage is the threads deform during assembly and they are hard to clock. Not well suited to reassembly.

BSPP hydraulic fittings have a parallel thread that requires a face seal gasket of some type. Very similar to an SAE ORB fitting.

Dan

 

[JohnDB]

... I'm only using the PTFE paste for the NPT connections. The BSPP uses o-rings.

Thanks I was curious to know if the BSPP and NPT were being asked to play with each other. They aren't, so I can relax

 

[North Idaho Wolfman]

Hydraulic fittings use the NPTF thread form which is designed to seal pressure tight without sealant. Also known as Dryseal pipe threads. In practice sealants are often used eith NPTF fittings and they are good to several thousand PSI. Their main disadvantage is the threads deform during assembly and they are hard to clock. Not well suited to reassembly.

BSPP hydraulic fittings have a parallel thread that requires a face seal gasket of some type. Very similar to an SAE ORB fitting.

Dan

Some Kubota (older) equipment also use BSPT (British standard pipe taper) similar threads as NPT.

 

[TheOldHokie]

Some Kubota (older) equipment also use BSPT (British standard pipe taper) similar threads as NPT.

That is correct. Kubota documentation used the now obsolete JIS designations PS (straight) and PT (tapered) for those forms.

In North America Kubota currently uses NPSF (straight) and NPTF (tapered) thread forms on their implements and outlet blocks.

In both standards a tapered male fitting can be used with a straight female fitting/port but requires the use of a thread sealant to make the joint pressure tight.

I am not positive but I dont think current British/ISO standards have an analog to American Dryseal pipe threads.

Dan

 

[Hugo Habicht]

Use a little common sense. Household plumbing and field sprayers do not crash and kill people.

I do not entirely agree. There is a company called Solo that used to make engine driven backpack sprayers. Internally this device was referred to as "winegrowers death" because it had the tendency to explode

 

[TheOldHokie]

I do not entirely agree. There is a company called Solo that used to make engine driven backpack sprayers. Internally this device was referred to as "winegrowers death" because it had the tendency to explode

I will make a note of that

Dan

 

[Runs With Scissors]

I asked a similar question recently. Lots of choices/opinions.

I used Rectum-sealer for my “shop air” ongoing, never ending, always changing project.

I have no idea if it’s “the best” or not.

But it seems to work plenty good.

I was not concerned with “mil specs” nor “aviation applications” when I bought it though.

Call me crazy, but since I was at Menards, and it was there on the shelf, I decided to “risk it”.

No leaks ………………………...so far.


Side note: I like the Blue monster picture best; However, I like purposely mis-spelling the name Rectum-seal even better………so thats the REAL reason I bought it.

 

[TheOldHokie]

Side note: I like the Blue monster picture best; However, I like purposely mis-spelling the name Rectum-seal even better………so thats the REAL reason I bought it.

That may be the most rational/honest reason anyone has given to date.

Dan

 

[John T]

Rectum seal #2 would be perfect....

 

[McMXi]

Thanks I was curious to know if the BSPP and NPT were being asked to play with each other. They aren't, so I can relax

Good grief!! You thought I was going to thread BSPP into NPT!! How dumb would I have to be to do that? The only reason why I'm using an adapter is that I couldn't find 1/2" Ag couplers that have 3/8 BSPP male threads on them like the piece of junk Faster ones do.

I have rebuild kits for the six Faster couplings and will put them on the "for sale" forum in the hope that someone might actually want to use them, with full disclosure that I have very little regard for them.

 

[hedgerow]

i'm replacing my original Teejet Control Valve AA17L with a new one, and concerned about the best product to use for attaching the green leaf fittings.

I was about to purchase the Blue Monster Thread Seal Tape, but just not sure if that's what is needed.

I need to make sure I use the correct product to prevent any leaks....so......looking for suggestions based on your experience. Thanks for any and all help!!

I will throw out my two cents. When I walk into the big Ag spray parts supply store they have Jomar thread seal and Rector Seal 21 Black laying on the counter for sale. Years ago the counter man I still trust today said Rector seal all the way. That's all I have used for years on sprayers, tenders and any sprayer components with zero issues. Sometimes on a two or three inch diameter fitting I will use some tape also but not the cheap stuff from the box stores.

 

[McMXi]

Thanks I was curious to know if the BSPP and NPT were being asked to play with each other. They aren't, so I can relax

A picture is worth a thousand words right? The Summit Hydraulics couplers arrived today but I'm still waiting on the PTFE paste that was supposed to be here last week. You can see the arrangement of the coupler and adapter (screwed in hand tight) which will replace the Faster 3CFPV couplers.