JIC vs NPTF

[newbury]

From a long thread, far far away

<snip>
NPT fitting are not designed to be used over and over. You crush the threads every time you tighten.

Try Loctite 542 red.

J_J - Is there any "rule of thumb" on how many times to reuse versus replace?
<snip>

Just reuse the NPT fitting until it leaks to much.

Yep, JIC are alot better. But if your hoses are NPT already, you can get some NPTM fittings to put between the hose and whatever. They are like a JIC in that the seal requires no sealant, and seals against a flare. Just on the inside instead of outside.

Looking at discounthydraulichose.com and a couple of other sites all the QD's or QC's seem to come in NPTF.

Is there some reasoning behind this? I'm just trying to understand why.

 

[s219]

Almost all the times I have seen JIC fittings, they are used for post-assembly,swapping, or in cases where you need to be able to set the proper angle/position of a hose or fitting. Almost all the times I have seen NPT fittings, they are meant to be semi-permanent and used in places where it won't matter how far you have to turn the fitting to tighten it.

So stuff that just spins on and never gets touched again tends to be NPT. Stuff that has to be positioned, or swapped, or attached in a post-assembly state is almost always JIC. Most construction equipment hoses I have seen are all JIC.

Something like a QD/QC will be snugged on to the end of a hose or the end of an outlet, and it won't matter how much you need to tighten it to snug down since it's axisymmetric. So that's a perfect arrangement for NPT.

 

[kennyd]

You can get good name brand (Pioneer/Parker, Safeway) QDs with ORB threads, but NPT are just very popular here in the U.S.

 

[newbury]

Which brings up another question - which term is preferred QD or QC?

 

[kennyd]

Which brings up another question - which term is preferred QD or QC?

Depends on what forum, what time of day, what part is in power, and how the stars align. Both are equally accepted.

 

[Leejohn]

It is a coupler. QD can also be a QRC.

 

[kennyd]

It is a coupler.

What couples, can also Disconnect