When Is 1/4" Not 1/4"?

[crokett™]

when its plumbing. At the BORG was holding a water line that has 1/4" fittings for the fridge. Yet it doesn't fit any of the 1/4" fittings in the plumbing department. The fitting broke on the line attached to the fridge, I was trying to replace it. I hate plumbing. 1/4" NPT is not the same as the 1/4" fittings on a refrigerator.

[Mr_Mike]

Shouldn't that be 1/4 " compression, not NPT?

[who]

yep, compression on the fridge....

[crokett™]

Mr_Mike said:

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Shouldn't that be 1/4 " compression, not NPT?

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Why is there a difference? Why can't 1/4" just be 1/4"? Either a) make all plumbing fixtures use the same fittings, or b) standardize on them so that 1/4" is universal.

[theeviltwinn]

Different fittings for different applications.

Twinn

[Robert Adams]

Different material. Npt is pipe thread heavy steel pipe. The fridge uses copper or plastic. The standard is the interior pipe diameter not the construction of the pipe.

[JGrout]

crokett™ said:

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[blockquote]Mr_Mike said:

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Shouldn't that be 1/4 " compression, not NPT?

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Why is there a difference? Why can't 1/4" just be 1/4"? Either a) make all plumbing fixtures use the same fittings, or b) standardize on them so that 1/4" is universal.

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[/blockquote]

Pipe threads are tapered

compression threads are not tapered and much finer.

Accuracy has a place....

[A Squared]

JGrout said:

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Pipe threads are tapered

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Not all pipe threads are tapered. There's also NPS threads which are straight. They're used on conduit

[A Squared]

crokett™ said:

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[blockquote]Mr_Mike said:

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Shouldn't that be 1/4 " compression, not NPT?

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Why is there a difference? Why can't 1/4" just be 1/4"? Either a) make all plumbing fixtures use the same fittings, or b) standardize on them so that 1/4" is universal.

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[/blockquote]

It may be a pipe/tubing thing. "pipe" diameters are nominally inside diameter (very nominally sometimes) while "tubing" diameters are based on outside diameter.

[crokett™]

It doesn't make it any less annoying. the other complication was the line on the fridge is 5/16" OD. No one has 5/16" fittings locally not even the pro shops. I ended up with a 5/16" to 1/4" reducing coupling and a universal plastic line that has a 1/4" compression fitting on it. It's not pretty but it doesn't leak.