Lock-Nut to Barb Drip Tubing Coupler | 16 & 20 mm

A lock-nut to barb drip tubing coupler joins two connection styles in a straight run. One side has a blue retaining nut, while the other has a stepped black barb. Choose this fitting when your irrigation assembly needs that transition, then match each line end to its own connection.

Four listed combinations

The available selections are 16 × 16 mm, 16 × 20 mm, 20 × 16 mm and 20 × 20 mm. Equal-size options keep the nominal dimensions the same across the joint; mixed-size options accommodate different listed ends. Check a mixed-size label against the actual lock-nut and barb sides before ordering.

Check more than the diameter

Identify which line uses the retaining nut and which uses the barbed connection. Compare tubing dimensions, line construction and the intended retention method at each end. A nominal 16 mm or 20 mm description alone does not prove that every irrigation tube or tape will fit. Check both ends independently before purchasing fittings for a complete row.

Prepare sound line ends

Switch off the water supply before fitting the coupler. Cut damaged tubing back to a clean, sound end and remove dirt from the connection area. Seat each compatible line fully and secure the retaining nut in its intended position. Avoid forcing a mismatched line over the barb or using the nut to compensate for an incorrect fit.

Inspect the completed joint

Support the adjoining lines so movement does not pull on the connection. Restore water gradually and check both ends for seepage or shifting. Recheck during the first watering run and turn off the supply before correcting a loose joint. Plan any branch or end closure with fittings that match the connected lines.