Help me identify compression fitting on air compressor

[wolfsburged]

I am trying to determine what type of fitting this is, with the end goal of converting to standard 1/2" compression fittings.

This is a 80 Gal, 5HP Kobalt for reference.

From the pump head I have a male thread which had a compression style tube fitting, however the ferrule is not like any I normally see. The male threads on the compressor side are really close to 1/2" NPT but are slightly larger in diameter. The thread pitch seems the same. I can thread the nut from the compressor line loosely onto a 1/2" NPT pipe but it is clearly not right.

Maybe a metric fitting?? Doesn't appear to be tapered like NPT either.

Shown with 1/2" NPT ****** for size comparison:

 

[engineer2]

Looks like a compression fitting to me. If none of the US sizes will fit the tube, it may be metric. What is the OD of the tube?

 

[GYPSY400]

Metric pipe thread is known as BSP ( British Standard Pipe) and to make it more confusing there are two types: BSPT ( tapered) and BSPP ( parallel). Also, even though it's metric thread pitch it is sized standard 1/2", 3/4" etc. The best thing to do would be to go to a hydraulic fitting ( I recommend a place that sells Parker brand as they are big overseas) store and pick up some 1/2" BSP female fittings - 1 parallel and 1 tapered and see which fits best, perhaps take your tube that has the nut on it to make sure.


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[bigredmf]

Is there anything stamped on the face of the nut.

The ferrule does not look like a metric ferrule. What is the od of the tubing?

Not to split hairs but British thread is not metric it is imperial.

Red


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[bigredmf]

After reviewing the pics on my confuser Vs the Ipad I want to amend my observation.

That is a metric ferrule.

I am rather confident that is a 12 mm Heavy Series Metric Fitting

12S 12mm Tube M20x1.5 Thread

Enjoy

Red

 

[Hornman]

That pipe thread is probably NPS, not NPT. Straight thread, not tapered. Since the threads are not tapered, they will be larger diameter on the end than a NPT fitting.

 

[ibedayank]

http://www.sealconusa.com/catalog/e-srf-cat/49-Technical-Info-Thread-NPT-Metric-PG-BSPP.pdf

BSPT/ British Standard Pipe Thread has not a damn thing to do with NPT as the threads are cut at 55 degrees not the 60 degree of ntp or metric threads. The other Thread that is cut at 55 degrees is Whitworth

 

[premierplayer]

That pipe thread is probably NPS, not NPT. Straight thread, not tapered. Since the threads are not tapered, they will be larger diameter on the end than a NPT fitting.

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