Cheap Chinese quick connector

[airgunfans]

Recently there has been two independent reports about the retaining rings of female quick connectors splitting during use so I did some searching in Taobao ( essentially Aliexpress in China ) trying to find a stronger one.

I managed to find a stainless one having the retaining ring 25% thicker than that of the connector came with the gold filter. It’s labelled as vendor 2 in the following pictures. The cost is 50% higher than the stainless connectors that I am using ( vendor 1 ) but still very cheap ( less than 3 USD each ). I have never seen any quick connnectors for airguns that look as beefy as this one. Despite it's beefier look, the vendor just claims that the connector is rated for 4500 psi instead of anything higher. 

View attachment MTUzODMxOTY1Ml8yMDE1OTQ5MDYwNWJiMGU1MjQ5NGNkMzMuOTE5Mzg0OTBf5rC45oGGLeS4iua1t+WHseWFiy3kuIDlk6UgYm90dG9tIGxvdyByZXNvbC5qcGc=

Another potential problem is the deformation of the balls. There has been reports on balls dropping out of the connector and I suspect that this is due to deformation of the balls as shown in the following picture. These balls are taken out from the stainless connector of vendor 1 in the picture above after about 8 filling sessions.

I believe these balls are not those hardened type used in ball bearings but just made of mild steel or stainless steel which is even softer. I am going to replace them with harder balls of hardness HRC 62-65. Hope this will keep my set up safer.

 

[willy]

Wow" great review" never seen anybody do a indeth research on the fittings?

 

[Stefanjan]

Nice comparisons. I check my connectors everytime i use my compressor.

 

[Tweeter]

I had to swap my gold QD out because it was forming dimples on the Air Venturi male QD due to a loose fit. I just bought some high pressure fittings to connect my micro bore to the compressor filter and did away with the quick disconnect. Better safe than sorry.





M10 x 1 to 1/8 BSP and an 1/8 BSP coupling

 

[douger]

I use all f x ones I had laying around they seem better built 

 

[tibor]

Wow" great review" never seen anybody do a indeth research on the fittings?

crazy huh!

why not purchase those here in the usa..

 

[Hynzie]

great info something we dont see a lot of TOM CAT did a video on the mis matching and safety issues that come up ,,the foster fitting i use is the extended foster fitting from BEST fittings UK SPAW and DONNIE FLA now carry this item a must for IMPACT owners ,really nice PAT

 

[Eaglebeak]

I had to swap my gold QD out because it was forming dimples on the Air Venturi male QD due to a loose fit. I just bought some high pressure fittings to connect my micro bore to the compressor filter and did away with the quick disconnect. Better safe than sorry.





M10 x 1 to 1/8 BSP and an 1/8 BSP coupling

Why don't you just connect the hose directly to the filter? If the thread is wrong, get a hose with M10x1 male ends or cut a new thread over the 1/8 BSPP existing one. The fewer joints the better.

 

[airgunfans]

I had to swap my gold QD out because it was forming dimples on the Air Venturi male QD due to a loose fit.

I wont worry too much about those dimples on the male connector as long as they do not extend outside the groove. Each ball is pressing against the shoulder ( edge of the groove ) of the male connector at just a single point so the pressure ( = force divided by contact area ) is tremendous. Some local deformation of metal is no surprise unless the metal is very hard. Once deformed, the metal will be hardened through a process called work hardening . The pressure will also be reduced a lot because each ball is now pressing against a surface with perfectly matched curvature instead of a single point. Because of these two reasons, the dimples will stop deepening further.

dimples formed on my stainless male connector after the first use : 

after multiple use : 

Although I believe that dimples on the male connector is nothing to worry about, those formed on the balls is a concern because if the balls are out of shape, the retainer ring can get jammed in place. Furthermore, there is the chance that the balls will not be able to hold the male connector in place and that will be a big safety hazard. That’s why I am going to replace the balls with those harder type used in ball bearings. They are very cheap. 50 pieces shipped cost about just one USD.

 

[cosmic]

Links please..

 

[airgunfans]

Links please..

Umm.... the link is all in Chinese so it may not be very useful. I think the regular stainless connector is already OK , just need to replace those balls which are too soft.