What Size Is My Drip Tubing?
The tubing used for drip irrigation mainline varies in size. Even drip hose referred to as "1/2" drip tubing" will differ depending on where it was purchased. The inner and outer diameters vary slightly between tubing numbers. This is especially important when 
adding on to an existing drip system. An easy way for you to tell what size mainline tubing you have is by looking at the inner compression ring of the fitting as they are color coded. Compression fittings fit over the outside diameter of the tubing.Compression fittings have color coded rings that correspond to tubing sizes.
Refer to the table below and match the tubing size with the appropriate fitting rings.
| Drip Hose US Dimensions (inches) |
|||||
|---|---|---|---|---|---|
| Tubing # | Size (commonly called) | Inner Diameter | Outer Diameter | Wall Thickness | Compression Fitting Ring Color |
| 185 | 1/8" | 0.125 |
0.185 | 0.030 | n/a |
| 220 | 7/32" | 0.160 | 0.220 | 0.030 | n/a |
| 250 | 1/4" | 0.170 | 0.250 | 0.040 | Orange |
| 307 | 5/16" | 0.250 | 0.307 | 0.028 | Grey |
| 350 | 11/32" | 0.250 |
0.350 | 0.050 | n/a |
| 455 | 3/8" | 0.375 | 0.455 | 0.040 | Red |
| 580 | 1/2" | 0.500 | 0.580 | 0.040 | Yellow |
| 620 | Raindrip 1/2" | 0.520 | 0.620 | 0.050 | Green |
| 700 | 1/2" or 5/8" |
0.600 | 0.700 |
0.050 | Black |
| 710 | 1/2" or 5/8" | 0.620 | 0.710 | 0.045 | Blue |
| 830 | 3/4" | 0.720 | 0.830 | 0.055 | Grey |
| 940 | 3/4" | 0.820 | 0.940 | 0.060 | Black |
| 940 | 3/4" | 0.830 | 0.940 | 0.055 | Black |
| 1200 | 1" | 1.060 |
1.200 | 0.070 | n/a |
