Thread tape, thread sealant, or ????

[TheOldHokie]

You're telling me stuff I already know. I know what fittings I have, I know the type of thread, I know they use an o-ring. I had to know all that in order to swap them out for the Summit Hydraulics Ag couplers and adapters. What I wasn't aware of is that the couplers that came on my $60k tractor four years ago are now obsolete.

Out of interest, $89 x 6 = $534 so compare that to what I paid for the Ag couplers and adapters. I paid $88.83 for all six 1/2" Ag couplers and $58.92 for the six 3/8 BSPP-1/2" NPTF adapters for a total of $147.75. That $386 difference can go towards the QH20 that I ordered yesterday.

Great. That would be your choice.

Hopefully you wont accidentally drop your mower and yank the ports out of that valve stack. Yes Virginia, that can and does happen.

 

[McMXi]

Great. That would be your choice.

Hopefully you wont accidentally drop your mower and yank the ports out of that valve stack. Yes Virginia, that can and does happen.

I pull a 4,000 lb RC3712 around with the tractor and it's not pulling any hoses out of couplers. I also pull an 8ft disc harrow around and that's not going anywhere either. I pay attention to how they're connected to the tractor in the same way I pay attention to how trailers are connected to my trucks. The cutter has a safety chain and I can easily add one to the disc harrow.

I don't have anything more to add re the swap. I jumped in this thread because I knew I'd be using PTFE paste rather than tape and figured it was relevant to the discussion.

 

[JohnDB]

Good grief!! You thought I was going to thread BSPP into NPT!!

It does happen . In this country due to imported equipment from different countries we get a mix of BSP and NPT, but most people assume the thread is BSP. In Canada a relative observed tradesmen regularly force-fitting NPT instrument connections into BSP threaded housings. I suppose it must have worked, for a while anyway.

This thread has been very instructional for me because I didn't realise that there were surge resistant high flow couplings. Thanks for sharing.

 

[TheOldHokie]

It does happen . In this country due to imported equipment from different countries we get a mix of BSP and NPT, but most people assume the thread is BSP. In Canada a relative observed tradesmen regularly force-fitting NPT instrument connections into BSP threaded housings. I suppose it must have worked, for a while anyway.

This thread has been very instructional for me because I didn't realise that there were surge resistant high flow couplings. Thanks for sharing.

There have been multiple cases here on OTT of people unknowingly mixing incompatible thread forms, fitting types, and quick couplers. Pipe fittings gooped up with thread sealant and jammed into SAE ORB ports is another common one. Then they wonder why they have leaks and complain about defective parts.

Its all too common and you see it on all of the tractor forums.

Dan

 

[Lil Foot]

The best thread sealant I've ever used (by orders of magnitude) is this stuff:

But they apparently went out of business, couldn't find it anywhere.

It has (apparently) resurfaced as this stuff:

I have some on order.

 

[GreensvilleJay]

so after 4 pages , is this now considered similar to an 'oil' thread ?

 

[JohnDB]

so after 4 pages , is this now considered similar to an 'oil' thread ?

No, or maybe it is for the experts... but I learned a couple of things as mentioned above. I don't find that with the oil and filter threads. And also, I didn't realise that Dryseal threads were an actual standard.

Dryseal seems a pointless standard to me anyway because 'to be safe' people usually recommend a thread sealant as well. Which means that Dryseal isn't much better than BSP tapered, which can be connected/disconnected multiple times (and needs sealant) without 'wearing out'. So that may be why, as @TheOldHokie says, there's no ISO or BS equivalent to Dryseal.

So I appreciate the OP raising the topic, and the ensuing discussion.

 

[Spam Bot]

Back in the 1960s, when Teflon tape was first introduced, it was intended for NPT that had been assembled and disassembled multiple times, with the sharpness of the threads worn off. Wrapping the threads with teflon tape would take up the slack and create a secure, leakproof seal. Now, you might ask who would be disassembling and reassembling threaded fittings that often, and the answer is very simple. Oil delivery trucks would require the pumps to be removed from the vanes on the workbench for rebuilding, which would be another example. Another was a truck that delivered tetrachloroethylene to dry cleaning establishments. The chemical would attack the pump seals, and they had to be resealed constantly. We used Rectorseal #5 with Teflon tape to reassemble these operations. Back then, Teflon tape was quite costly, and it was also much thicker than the stuff commonly sold in stores for homeowner use.

 

[TheOldHokie]

No, or maybe it is for the experts... but I learned a couple of things as mentioned above. I don't find that with the oil and filter threads. And also, I didn't realise that Dryseal threads were an actual standard.

Dryseal seems a pointless standard to me anyway because 'to be safe' people usually recommend a thread sealant as well. Which means that Dryseal isn't much better than BSP tapered, which can be connected/disconnected multiple times (and needs sealant) without 'wearing out'. So that may be why, as @TheOldHokie says, there's no ISO or BS equivalent to Dryseal.

So I appreciate the OP raising the topic, and the ensuing discussion.

Since we are learning not arguing I will add this.

NPTF/NPSF (Dryseal) is a more demanding standard, harder to manufacture, and requires proper assembly technique to work. By the very nature of the design it is not well suited for reassembly.

Quite by accident I discovered that Kubota currently uses NPSF (straight threads) for the female ports in many of their hydraulic outlet blocks. The reason for that is almost surely because they are easier (and cheaper) to tap at the factory. The dealer techs assemble that "by the book" using a NPTF male hydraulic fitting and (gasp) PTFE tape.

All of that is 100% in accordance with the ANSI/ASME Dryseal standard and ISO/BSP does have an analog for the same reason - ease of manufacturing. ISO/BSP allows male R (tapered) thread to be paired with a female G (straight) thread and when used with a thread sealant it produces pressure tight joints.

The fittings in the plumbing section of your box store are generally NPT and poorly made at that. Bubba the plumber doesnt understand any of this thread standard nonsense so he goops everything up with sealant or tape to be safe. Time is money so he works fast and in the process occasionally contaminates the system with whatever sealant he is using. When he is called back because the customer's furnace wont light he discovers bits of dried PTFE paste sealant in the gas valve and bills accordingly

Dan

 

[hagrid]

Since we are learning not arguing I will add this.

NPTF/NPSF (Dryseal) is a more demanding standard, harder to manufacture, and requires proper assembly technique to work. By the very nature of the design it is not well suited for reassembly.

Quite by accident I discovered that Kubota currently uses NPSF (straight threads) for the female ports in many of their hydraulic outlet blocks. The reason for that is almost surely because they are easier (and cheaper) to tap at the factory. The dealer techs assemble that "by the book" using a NPTF male hydraulic fitting and (gasp) PTFE tape.

All of that is 100% in accordance with the ANSI/ASME Dryseal standard and ISO/BSP does have an analog fir that and for the same reason - ease of manufacturing. ISO/BSP allows female R (tapered) thread to be paired with a male G (straight) thread and when used with a thread sealant it produces pressure tight joints.

The fittings in the plumbing section of your box store are generally NPT and poorly made at that. Bubba the plumber doesnt understand any of this thread standard nonsense so he goops everything up with sealant or tape to be safe. Time is money so he works fast and in the process occasionally contaminates the system with whatever sealant he is using. When he is called back because the customer's furnace wont light he discovers bits of dried PTFE paste sealant in the gas valve and bills accordingly

Dan

View attachment 170228

View attachment 170229

Why are there genders applied to these components? Are there similarities between these components and mammalian reproduction?

 

[TheOldHokie]

Why are there genders applied to these components? Are there similarities between these components and mammalian reproduction?

@hagrid there are obvious physical similarities but missing some function. Drop your drawers and compare with what you see on the barnyard ewe. Physical interoperation is possible but wjthout reproductive function. Please take care not to be seen in the process and do not attempt a test fit

Dan

 

[McMXi]

The fittings in the plumbing section of your box store are generally NPT and poorly made at that. Bubba the plumber doesnt understand any of this thread standard nonsense so he goops everything up with sealant or tape to be safe. Time is money so he works fast and in the process occasionally contaminates the system with whatever sealant he is using. When he is called back because the customer's furnace wont light he discovers bits of dried PTFE paste sealant in the gas valve and bills accordingly

Hard not to agree with this. I've seen many people wrap a ridiculous amount of PTFE tape around a fitting with no thought as to what the tape is supposed to be doing, as well as getting sloppy about where the tape is applied on the fitting. I think some basic instruction in how to properly and effectively apply PTFE tape would be a good thing, but the short version is to apply the least amount possible that accomplishes the intended task.

I will confess that it's easy to fall into the "more is better" trap with so many things in life, and PTFE tape is one such example.

 

[TheOldHokie]

I will share another personal anecdote.

Late summer of 2024 I hired a local "handyman" to remove my old commercial gas range and install a new replacement. When hooking up the flex gas line he smeared the flare ends of the two adapters with the same PTFE paste he used on the taper pipe ends. When I objected he insisted it was required. First thing I did after he left was pull the range out and clean that crap off.

Dan

 

[McMXi]

I will share another personal anecdote.

Late summer of 2024 I hired a local "handyman" to remove my old commercial gas range and install a new replacement. When hooking up the flex gas line he smeared the flare ends of the two adapters with the same PTFE paste he used on the taper pipe ends. When I objected he insisted it was required. First thing I did after he left was pull the range out and clean that crap off.

Dan

I've seen more than a few use PTFE tape on fittings that simply don't require it. You'll see this on YouTube all the time, as well as five wraps of tape around a fitting.

 

[Runs With Scissors]

………….as well as five wraps of tape around a fitting.

Well, if “a little is good, then more MUST be better!” …..right?

 

[Spam Bot]

Before Teflon tape, we used pipe dope and cotton thread to take up the gaps.

 

[TheOldHokie]

Before Teflon tape, we used pipe dope and cotton thread to take up the gaps.

Oakum and poured lead is the only reliable seal

Dan

 

[Spam Bot]

Oakum and poured lead is the only reliable seal

Dan

Only if it is properly pounded in place after pouring.

 

[North Idaho Wolfman]

Good old pine sap will seal anything!

 

[Trustable]

Okay, so I’ve read through this whole thread and have a question to add on. I have only ever used the cheap hardware store ptfe/Teflon tape for sealing and I absolutely hate it. For general water use cases, would it be accepted that a general purpose liquid sealant be a better option? I’m not a plumber by any means so I have been learning a lot from this thread. Most of the experience I have is related to soldering copper and installing fixtures and toilets. Which it seems recently most fixtures I’ve bought come with a small roll of tape and/or some sort of seal inside.