These connect directly. Duotight ball-lock liquid QD (8mm) mates with EVABarrier 5mm ID x 8mm OD line without an adapter. Sealing method, the real-world trap, and the exact part to buy.
Updated 05 September 2026.
Connect Duotight ball-lock liquid QD (8mm) to EVABarrier 5mm ID x 8mm OD line
How to join black QD, 8mm push-in tail and 5 mm ID / 8 mm OD, and what stops it leaking.
These connect directly. Duotight ball-lock liquid QD (8mm) mates with EVABarrier 5mm ID x 8mm OD line without an adapter.
The two ends
- End A
- Duotight ball-lock liquid QD (8mm) (black QD, 8mm push-in tail)
- End B
- EVABarrier 5mm ID x 8mm OD line (5 mm ID / 8 mm OD)
- A seals on
- O-ring over the post shoulder; 8mm push-in O-rings on the tube
- B seals on
- the 8mm OD is what a Duotight 8mm or John Guest 5/16 collet grips
- Part needed
- none, direct fit
A Duotight liquid ball-lock disconnect with an integrated 8mm push-in takes EVABarrier 5mm ID x 8mm OD beer line straight into the black body. The wider 5mm bore suits a beer run, and the 8mm wall is what the push-in grips.
Keep this on the liquid post, since it is keyed to that side. The 8mm OD is what seats in the push-in, so match the fitting to the outer size, not the 5mm bore, and clamp nothing here because the push-in seals on O-rings, not a barb.
Related connections
Questions and answers
Connect Duotight ball-lock liquid QD (8mm) to EVABarrier 5mm ID x 8mm OD line?
These connect directly. Duotight ball-lock liquid QD (8mm) mates with EVABarrier 5mm ID x 8mm OD line without an adapter.