Thread: Airline fittings - Which Type?

Originally Posted by BobL

Should be dead easy, brass has more than 3 times the density of aluminium.

Different Bunnings stores may have different products, and the range changes over time. The nice looking Anodized Aluminium stuff was sold off in recent months for half price or less - I guess they just had too many returns and complaints on these very very inferior Nitto clones (I bought some to try and was utterly disgusted). The chrome plated Nitto copies are steel (not stainless, I know because I bought one and it did rust after less than one year). They are actually exactly the same as the Chinese made ones on ebay and Alibaba, only that Bunnings sells them much dearer. Bunnings also has (or used to have) some brass fittings, but I have never tried them and cannot commet.

I just checked the Nitto connection I had on my reticulated air system

Currently in use I have
Aluminium: 5 female and 4 male fittings. BTW only the release ring on the Female fittings are Al, the rest of the fitting is steel.
All steel. 8 female and 7 male.
Brass: 1 male and 1 female fitting.

During the last couple of years I have been keeping a pretty close watch on possible leaks in my system by performing a weekly water and detergent test.
I've have more than a fair share of leaks but the only actual fitting that has "leaked" was (probably my oldest ~20 years) all steel female fitting with a sealing problem possibly corrosion.

This could be because I rarely connect and disconnect hoses with 4 of my 7 outlets have hoses permanently connected to them.
One hose is permanently connected to a plasma cutter, 2 hoses have air guns connected to them, and the fourth hose has a tyre pressure gauge/inflator, alternated with a log hose and another air gun. I also have another short hose that I occasionally move between the other 3 outlets

All of the other leaks were from, cheap/damaged air guns, fittings to hose connections, or the BSP fittings I used in my system. So far none of the Al fittings have had a problem but I guess time will tell but I won't replace them till they leak.

Most of the BSP related leaks were from BSP threads I cut myself or the Heath Robinson array of various adapters I used to adapt the 20 mm glav pipe to the 1/4" BSP Nitto fittings.

This one uses a part of an old tap into which I tapped a 1/4" BSP thread.


The threads I cut myself in various bits of plumping etc were either not long enough or I simply did not use enough teflon tape.
Recently I purchase a bundle of adapters that go direct from a BSP 20 mm to the 1/4" BSP Nitto fitting and I have been retrofitting these as the others leak

My hoses are short (3m) lengths cut from a longer roll or air hose and attached to hose barbed Nitto fittings with a SS hose clamp. What happens in time is the hose shrinks and the clamp needs tightening.

The dud air guns I threw away. They typically crack around the dinky toy metal connection to the Nitto fitting.

What I need to find is a source of decent air guns.
Any suggestions?

Originally Posted by BobL

..............................

The dud air guns I threw away. They typically crack around the dinky toy metal connection to the Nitto fitting.

What I need to find is a source of decent air guns.
Any suggestions?

See two posts above. "Air Boy" blowguns are still made in Denmark. They make a whole range. Cost a little more than those that crack or rust or leak. Of course.

Has anyone found the cure for the nito cloned leaks??
The washer/grommet inside the female fitting gets compressed or worn and can be turned around
the other way to get a bit more leak free life out of it.
I have tried a few times over the years to get replacement washers to no avail so I just buy new female
fittings from the local market, 5 bucks ea I think.
So far I haven't come across anything else that will do the job, I reckon if one had rubber or
neoprene sheet of the correct thickness then they could be simply wad punched out, has anyone tried
this ?

Originally Posted by Chris Parks

That was me and I have been using them for many years, catch the sliding sleeve on a floor irregularity and they will separate. I have seen it, experienced it and it is a known problem with the fitting.

Same here Chris, if need to use my extension hose's I always wrap insulation or duct tape around the fittings.

Ahhh, full book now, so if brass is three times the density of aluminium it should be heavier, right? I wonder if dense people are heavier than smart people??? Brass also has a high gold content I believe - hence the weight and colour.

I also have trouble distinguishing between lead and aluminium (similar colour). Aluminium would be heavier, right? Lead is pretty lightweight I think, it's used in aircraft, boats and stuff like that. And being non toxic it would also be great for drink cans, food containers, stuff like that.

[QUOTE=shedhappens;1837721]Has anyone found the cure for the nito cloned leaks?? The washer/grommet inside the female fitting gets compressed or worn and can be turned around the other way to get a bit more leak free life out of it. I have tried a few times over the years to get replacement washers to no avail so I just buy new female fittings from the local market, 5 bucks ea I think. So far I haven't come across anything else that will do the job, I reckon if one had rubber or neoprene sheet of the correct thickness then they could be simply wad punched out, has anyone tried this ? /QUOTE]



It is both the material and the fit and finish that make a great differece. But also the design of the self sealing valve is VERY different. To understand, you need to buy one genuine Nitto coupler, and just visually compare it to Chinese compatible couplers that you have. I try to describe the differences that I see with my naked eyes - no better, I take pics:

1.jpg
Male fitting, left Nitto, right Chinese clone. Both brand new and unused. Notice the very pronounced difference in surface finish?

2.jpg

Male fitting, left Nitto, right Chinese clone. Notice the bright spot on the inside of the Chinese clone, that is the chrome plating peeling off! Over short or long, that hard chromium debris is going to end up inside your air tool. Or it may get caught in a seal and cause leaking.



3.jpg

Female fitting. Left a new unused Nitto. Right a used Chinese clone from Bunnings. Its body junction leaked, I tried to fix it with a copper washer. Just compare the surface finishes, no need for a caliper, just compare visually.




4.jpg

Left Nitto. Right Bunnings. can you see the different design of the self sealing valve? My picture is not showing it very well, but believe me by eye you could see its a completely different design. The Chinese thing is brass corored and has two small holes drilled in it sideways, with big burrs left - that is where the air must through. Not so on the nice Nitto valve, look it is made from SS. Now, I inserted into each female coupling the corresponding male fitting. First observation: It took MUCH more force and 5 times longer to put together the Chinese parts. Second observation, if I now blow with my mouth air through the fitting, I can clearly feel how the Chinese combination has less flow going through it. 20 to 30% less by feeling alone whilst blowing.



5.jpg

Nitto closeup, look at surface finish.



6.jpg

Chinese clone from Bunnings, compare surface finish with above. Wonder it leaks, if its valve seat is made the same way?





Believe me, trying to fix chinese copies is not worth it. Just go and buy the real thing.

Quite a difference in finish there. I also notice the Chinese fitting has more balls, five or six compared to four on the Genuine Nitto.

I've also noticed the prices for the Chinese rubbish are very close to that of the genuine Nitto fittings. Better profit margins I would guess...

Originally Posted by cba_melbourne

It is both the material and the fit and finish that make a great differece. But also the design of the self sealing valve is VERY different. To understand, you need to buy one genuine Nitto coupler, and just visually compare it to Chinese compatible couplers that you have. I try to describe the differences that I see with my naked eyes - no better, I take pics:

Thanks for going to the trouble to show us the comparison.
Convincing!

Jordan

Just a bit of a heads up on something that I learned a while ago. Araldite makes brilliant thread sealer - glad it does something well. I first came across this on fire appliances and while it probably isn't the most convenient thread sealer, it works really well and would be ideally utilised when you set up your system so that you could mix it up and then assemble half a dozen fittings at a time.
My personal favourites are either Loctite 569 Hydraulic sealant or Loctite 567 Master pipe sealant, unfortunately 567 will not work on poly fittings so it is either Araldite or teflon tape for them.

Originally Posted by cba_melbourne

See two posts above. "Air Boy" blowguns are still made in Denmark. They make a whole range. Cost a little more than those that crack or rust or leak. Of course.

What he said, being using Air Boys for years, lost my old one that must've been 15yrs old and bought an imitation and it ended up in the bin in a few days.

Once you've used Air Boy blowguns, you won't use anything else.

Originally Posted by Karl Robbers

Araldite makes brilliant thread sealer

For metal-to-metal connections, I use stuff called Loxeal - it's an anaerobic thread sealing snot you get from plumbing shops. No messing around with teflon and chasing leaks.

For metal to plastic you'd need to use epoxy. Or like the pool installers, silicone!

The brass Nitto fittings I bought from Bunnings are actually Nitto. After looking at CBA's pictures I had another look at the fittings I bought and they are stamped 'Nitto'. They also have 6 balls instead of the four as in CBA's.
Funny though, I just can't find any brass male fittings.

I've got to admit I'm a little surprised and amused that this subject has taken up 5 pages so far. All this discussion about types, brands and quality of manufacture, etc seems to me at least, a bit of a non-event.

I've always used Nitto style fittings (cause that was what was on the first compressor I bought) and have used a huge mix of brand name and cheap fittings over the last 25 years and have NEVER had a single failure. Or have been worried by how freely they flow.

Same with blow guns ... I've still got the cheapy I bought with my first compressor.

My advice ... don't sweat it. Also go with Nitto style fittings as they seem to be the most popular now days.

Yep I agree, I don't see how one blowgun could be better than another, all they do is blow air. The one I have is a cheapy, I bought it at the same time as my compressor, must be about 30 years old now.

Perhaps someone could explain why an expensive brand name blowgun would be better than a cheapy, it's beyond me!

I'm swapping over to Nitto fittings at the moment, only because I thought they would be easier to get - apparently I was wrong. I much prefer the Jamec style though, much easier to use.