CMB Ball lock QDs, wonky or just me?

[Michele Craft]

Hi all,

When we built our keezer last year using EVA 4mm ID, I put ball lock posts on our sankey couplers and am using CMB ball lock QDs to Duotight 1/4" female flare/PTC fittings. I am not thrilled with the CMB ball locks, specifically on the gas side.

It seems like tho the ball locks are seated on the post securely, any little movement/rocking has them pissing out co2. When we close the lid we're super careful with where lines are landing and all but it still makes me nervous. Are there other/better options? I did recently see some metal ball lock connectors, but don't remember the brand and don't honestly know if they'd make a difference.

 

[Bobby_M]

CMB is the worldwide standard. I would put German manufacturing QC against Chinese ball lock adapters. Change the orings out.

 

[Michele Craft]

I would agree, that's why I went with these. They've done this since new so I don't think it's an o ring issue (I assume you mean on the post as the cmb ball locks don't have them, just the 4 balls that recess in to catch the post groove.

 

[Bobby_M]

Yes, the seal is made with the orings on the male posts so I would be more suspect of those being worn, shrunk or just mis-sized before I would suspect the CMB disconnects being faulty.

The ball lock to sanke coupler adapters are what I suspect are Chinese and suggested might be out of spec. That could only be determined by putting a set of calipers on them to measure.

 

[Michele Craft]

Ah OK I see what you're saying. Do you happen to know the specs? I have calipers.

 

[Bobby_M]

The diameter inside the oring slot is 11.75mm and that's probably the most critical to avoid what you're seeing. With the oring in place, the max diameter at the oring is 16.5mm.

Make sure you're using lubricant on the orings.

 

[Michele Craft]

thanks for that info! I have 16.2mm at the oring tho I cannot get one off in a fashion that I thought wouldn't scratch the heck out of the oring so I can't easily measure the oring slot itself on the post. Once I get some spare orings, I'll not worry about marring the current ones and take one off to check for the 11.75mm