Air Compressor Fittings

[Zen Dog]

I've always (naively) assumed that there was one standard for compressor fittings. Mainly just because I've never heard anyone mention it. But clearly there isn't. And googling gives the impression that there are at least 2 in common use in the UK. "UK Standard" and "Euro XF". There are also a whole load of other acronyms in use (like "BSP") and it's not really clear whether these are compatible (or the same as) one of those standards, or something else.

This has come to a head because I have a compressor, a hose, and an existing blow-gun, and these all fit together securely and work as they should. They appear to be XF fitting. But I also have an OTC leakdown tester, and some other bits and pieces, and these also appear to be XF. But they're actually narrower, and they don't fit securely, falling out when you try to use them. It seems unlikely that the OTC tester would be "UK standard" as it's an american product.

https://i.imgur.com/ZoO4hMFl.jpeg

Image is terrible I'm afraid, but basically -
C fits my compressor, and is identical in design with B.
A and B fit securely and properly.
D does not fit securely into A, leaking and falling out.
D appears to be a couple of mm narrower than B and C.
D isn't an anomaly, I have a couple of other things with this fitting.
Absolutely none of them have any markings on them, and the page for my leakdown tester (And the manual) doesn't mention it. https://www.otctools.com/products/cylinder-leakage-tester-kit

So my questions are -
What are these different fittings? If we assume that A, B and C, are XF fittings, what is D? How do I definitely identify them?
Adaptors from one standard to another don't seem to exist, so ultimately, how do I connect D to my compressor?
____________________
Current - '94 VFR750FR (Dead), '00 VFR800FI, 2011 CBF125 Previous - '10 Street Triple R, '92 MZ ETZ301, '05 TTR250, NSR125R, KMX125, "Honda" Win (chinese copy of an old Honda design with a C90 engine)
My bike trip around S.E. Asia 2010/2011

[stinkwheel]

A few different quick connectors. I have PCL 1/4 ones on my air tools which have a 1/4" BSP thread on them (BSP = British Standard Pipethread). As it suggests, british standard. Pretty sure the XF fittings also use 1/4 BSP.

Don't take that as the actual measurement though. 1/4" BSP actually has a major diameter of 0.518". 1/2" BSP has a major diameter of 0.825"

Yours LOOK like 1/4" BSP but you also get paralell and tapered (BSPT) forms. The BSPT is visibly tapered. I have also seen pneumatic fittings with 3/8, 5/16 and 1/2" BSP. But 1/4" BSP is the most common by far, be it paralell or tapered.

Now add in America... They just have to be different, as well as a refusal to use metric, they will also refuse to use Imperial standards, but still referr to them as "standard". So if it's an American part, it could be NPT (National pipe thread) which they will just refer to as 1/4" or "standard" but has a different threadform to BSP.

So it's probably 1/4BSP BUT if one of your things is American, it could be 1/4NPT.

If it's Amazon/TEMU Chineseium special, all bets are off, could even be metric.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[cresad]

Hi

As an add on to above and to confuse you even further there are PCL fittings - https://www.pclairtechnology.com/couplings-adaptors/pcl-couplings-adaptors

and SCHRADER fittings - https://www.pclairtechnology.com/couplings-adaptors/schrader-couplings-adaptors

The best bet would be to go to your local pneumatic fittings shop and take what you have and get every thing to match or at least they can tell you better what you have.

Adam

[stinkwheel]

[Zen Dog]

That's all good information. But is the 1/4" BSP part just referring to the thread that connects to the hose? If it is, it's good that BSP is a mostly consistent standard, so that's a start. But it doesn't get me any further with the quick connectors.

I have managed to find out from my old order history that B (and therefore C and A) are definitely XF connectors, this one - https://www.screwfix.com/p/pcl-aa7102-xf-male-adaptor-plug-1-4-x-1-4/2015h

But that still doesn't help me with what D is. I only know it looks just like XF but it's slightly narrower. But then I found that page 23 of the PCL catalogue has an actual size adaptor profile comparison. I reckon I should be able to match them up with this and order an appropriate hose with fittings. I think in PCL terms, D is probably an "ISO B12" fitting. https://www.pclairtechnology.com/media/assets/product/documents/PCL-product-catalogue.pdf
____________________
Current - '94 VFR750FR (Dead), '00 VFR800FI, 2011 CBF125 Previous - '10 Street Triple R, '92 MZ ETZ301, '05 TTR250, NSR125R, KMX125, "Honda" Win (chinese copy of an old Honda design with a C90 engine)
My bike trip around S.E. Asia 2010/2011

[stinkwheel]

If it was me, I'd shitcan any of the fittings that don't fit with the system you've decided to use (basically whatever coupler sytem you chose to have on the end of your airline) and fit all your pneumatic tools with an appropriate fitting.

I bought a bag of male and female 1/4 BSP to PCL male fitings and fitted them on all my air tools. The compressor has a PCL female and the airlines all have one of each on either end. Everything connects to everything else.

The one in the picture (D) looks like it's a barb fitting into the hose? So cut/pull it off and replace it with a barb to *insert selected male fitting here*. No point fucking about with adapters, you'll lose them or it'll just annoy you and the correct fitting will be either the same price or cheaper. What's the point of having QD fittings if you land up fucking about with adapters to make them work?
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[sickpup]

I went through this a few years back and changed everything to XF as it has a higher through flow than the British Standard I was using.

Problem I had was every time I bought a new tool they came with either XF or Schrader. My big 14cfm compressor has 3/4 outlets and the British Standard fittings were restricting it's output so Windy guns were losing power (relative to what they should be). The XF's cured this problem.

The fitting on the hose I've seen before, has semi circular cut outs and often appears on cheaper European stuff from places like Aldi. I 'think' they are supposed to be compatible with XF but they aren't very secure.