Guide · Mainline fittings
Green, black or blue? DIG compression inserts by tubing OD
On DIG compression fittings, green is listed for .620-.630 in OD, black for .700 in and blue for .710 in. The part numbers, the rating, and why colors are per maker.
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Short answer
On DIG compression fittings, the insert color marks the tubing OD: green is listed for .620-.630 in, black for .700 in and blue for .710 in. Those colors are DIG's. Other makers' colors mean other things, so never read a color across brands.
DIG's three insert colors
- Green: DIG lists its green insert for tubing with a .620-.630 in OD.[1]
- Black: DIG lists its black insert for .700 in OD tubing. The same page gives two different lower bounds: one section says .690 in and another says .680 in.[1] Treat only .700 in as certain, and ask DIG before relying on the black insert for anything smaller.
- Blue: DIG lists its blue insert for .710 in OD tubing.[1]
Part numbers
| Color | Tubing OD DIG lists | Coupling | Tee | Elbow |
|---|---|---|---|---|
| Black | .700 in | C33 | C35 | C36 |
| Blue | .710 in | C43 | C45 | C46 |
DIG lists the C33, C35 and C36 for .700 in OD tubing and the C43, C45 and C46 for .710 in OD.[1]
DIG also makes two reducing couplings that join sizes:
- D50G (green) joins .700 in OD tubing to .620 in OD tubing.[1]
- D50B (blue) joins .700 in OD tubing to .710 in OD tubing.[1]
Our reducing joins guide covers both, and the other couplings that list more than one size.
Pressure
DIG rates its compression fittings for up to 60 PSI and recommends operating them at 15 to 35 PSI.[1] A pressure regulator upstream keeps the line in that band; see our pressure regulator guide.
Threaded ends are separate parts
A compression fitting with a threaded end has two numbers to match: the tubing OD and the thread. DIG lists hose-thread and pipe-thread swivel adapters as separate part numbers, for example 15-005 (.700 in OD x 3/4 in FHT) and 24-029 (.700 in OD x 3/4 in FNPT).[2] Raindrip advises matching hose thread to hose thread and pipe thread to pipe thread.[3] Our thread guide explains the difference.
Colors are not a cross-brand code
Color codes belong to one maker and one product line. Raindrip, for example, uses color on its drippers to mark flow: red for 0.5 GPH, black for 1 GPH, green for 2 GPH and yellow for 4 GPH.[3] A green Raindrip dripper says nothing about tubing size, and a green fitting from a brand other than DIG may not mean .620 in. Read the OD the maker prints on the package or product page.
A compression fitting from another maker
DIG's compression fittings are not in our catalog yet. Rain Bird's Easy-Fit compression fittings state their own range instead of using DIG's colors: 0.63-0.70 in OD.[4]
Picks that fit2 products
Choose EFC25-1PS for a coupling or EFT25-1PS for a tee, only for tubing between 0.63 and 0.70 in OD.
More on choosing
Rain Bird does not list Easy-Fit for .710 in tubing.
Choose the Rain Bird Easy-Fit EFC25-1PS for 0.63-0.70 in tubing
Rain Bird Easy-Fit EFC25‑1PS 1/2 in universal compression coupling (0.63‑0.70 in OD)
Compression tee for 0.63-0.70 in OD
Rain Bird Easy-Fit EFT25‑1PS 1/2 in universal compression tee (0.63‑0.70 in OD)
On Amazon, check that "Ships from / Sold by" is Amazon.com or the brand before you buy.[5]
Next
Questions
What do the colors on drip compression fittings mean?
On DIG's compression fittings, the insert color marks the tubing OD: green for .620-.630 in, black for .700 in and blue for .710 in. That is DIG's code; other makers use colors differently.[1]
Is a green drip fitting always for .620 tubing?
Only on DIG's listing, where green is for .620-.630 in OD. Raindrip, for example, uses green to mark a 2 GPH dripper, not a fitting size.[1][3]
Can a black-insert DIG fitting take .710 tubing?
DIG lists its blue insert for .710 in OD tubing and its black insert for .700 in OD, so use blue (C43, C45, C46) for .710 in tubing.[1]
What pressure are DIG compression fittings rated for?
DIG rates them for up to 60 PSI and recommends operating them at 15 to 35 PSI.[1]