Match the fitting to the tubing’s measured size
A barbed fitting pushes inside the tubing, so it is sized by the tubing’s inside diameter; a compression fitting grips the outside, so it is sized by the outside diameter, DripWorks explains. DripWorks’ ½-inch compression fittings fit tubing from 0.680 to 0.720 inch outside diameter, and Rain Bird’s Easy-Fit fittings fit any brand from 0.63 to 0.7 inch.
Which fitting does what
| Fitting | What it does |
|---|---|
| ¼-inch barbed connector (transfer barb) | Joins ¼-inch tubing or dripline to a hole punched in the ½-inch line |
| Tee and elbow | Branch or turn a line |
| Goof plug | Closes a hole punched in the wrong place |
| End closure (figure-8, end cap or plug) | Closes the end of a line |
| Tubing stake | Holds the line in place on the soil |
Pressure and leaks
DIG says barbed insert fittings are best used at pressures of 15 psi or lower, because tubing inside diameters vary. Rain Bird lists a wrong-size fitting among the causes of leaks: its 0.630 inch tubing needs 0.630 fittings, and another maker’s fitting may be a different size.
How many you need
Count one connector at the start of each row and one closure at its end, plus the tees and elbows your main line needs. The drip parts calculator counts them from your beds and rows. As an example of what a kit contains, Rain Bird lists barbed fittings, elbows, goof plugs and tubing stakes for its raised bed kit.
When it isn’t working
A leak at a threaded joint. DIG’s first check: a hose thread (MHT or FHT) joined to a pipe thread (FPT or MPT), for example a hose-thread swivel on a pipe-thread pressure regulator. Teflon tape will not seal that joint: use parts with the same thread on both sides.