Buying task · Mainline fittings
Drip mainline fittings, by tubing OD
Drip irrigation fittings grip a narrow size band. Pick compression, barbed or locking-nut fittings whose maker states a range that includes your tubing's OD.
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Short answer
Buy 1/2 in drip fittings by your tubing's outside diameter, not by the "1/2 in" label. Pick the connection type you want (compression, barbed insert or locking nut), then a fitting whose maker states a range that includes your OD, such as Rain Bird Easy-Fit at 0.63-0.70 in or Orbit 67466 at .620-.710 in. Where two sizes meet, use a reducing fitting made for that pair.
What mainline fittings do
Mainline fittings join, branch, turn and close the 1/2 in tubing that feeds your system. Each type grips the tubing a different way, and each grips only a narrow band of sizes. The makers state those bands as ODs or IDs, and those numbers are what decide fit.
- Compression: the tubing pushes into the fitting and is gripped on its outside, so the OD matters. DIG color-codes its compression inserts by OD: green for .620 to .630 in,[1] black for .700 in,[1] and blue for .710 in.[1]
- Barbed insert: a barb goes inside the tubing, so the ID matters. DIG labels its 1/2 in barbed fittings 16 and 17 mm.[2]
- Locking nut: a barb plus a nut that clamps the tubing. DIG lists its NUTLOC fittings for .530, .600 or .620 in ID tubing, described as .630 to .710 in OD.[3] Raindrip's Smart Loc coupling S5600UB lists .520 x .620, .600 x .700 and .620 x .710 in tubing.[4] Orbit's 67466 coupling is listed for .620 to .710 in OD and uses a nut you loosen to remove the tubing.[5]
The fitting types guide explains how each one grips.
The decisions, in order
- Your tubing's OD, and its ID for barbs. Use the measuring guide or the tubing size finder.
- Connection type. Compression fittings are the simplest to buy by OD. Locking-nut fittings cover the widest stated ranges.
- A fitting whose maker range includes your size. Rain Bird lists its Universal Easy-Fit compression fittings for 0.63 to 0.70 in OD.[6] Orbit's 67491 Drip-Lock coupling is a push-on fitting with a release tab, listed for .690, .700 and .710 in OD.[7] DIG's C33 coupling, C35 tee and C36 elbow are for .700 in OD,[1] and its C43, C45 and C46 are for .710 in OD.[1]
- Pressure rating. DIG rates its compression fittings up to 60 psi and recommends 15 to 35 psi.[1] Rain Bird lists Easy-Fit at 0 to 60 psi.[6] Raindrip says Smart Loc handles up to 50 psi.[4]
- A reducer if two sizes meet. DIG's D50G joins .700 in OD to .620 in OD, and its D50B joins .700 to .710.[1] See joining .700 tubing to .620 or .710.
- An end closure you can open. Orbit's 67468 end cap is listed for .620 to .710 in OD with a reusable nut.[8] The end closures guide covers the options.
Adapters are not interchangeable with barbs. Rain Bird says Easy-Fit adapters are not barbed fittings and are to be used only with Easy-Fit compression fittings.[6]
"Universal" fittings
"Universal" on a drip fitting means the maker's stated range, nothing more. Orbit's own wording for 67466 is "most major brands" of 1/2 in tubing, which it puts as .620 to .710 in OD.[5] If your tubing falls outside the stated range, the fitting is not listed for it. The universal fittings guide compares the ranges.
Reusing fittings
Locking-nut fittings are made to come apart. Orbit says you loosen the 67466 nut to remove the tubing.[5] Mister Landscaper describes its MLF 1/2 in poly fittings as reusable locking-collar fittings with built-in O-rings.[9]
How to choose
If your tubing is anywhere from about .620 to .710 in OD, or you are not sure which, a fitting with a wide stated range is the simplest buy. Orbit lists its 67466 coupling for .620 to .710 in OD.[5] Raindrip lists its S5600UB Smart Loc coupling for three ID x OD pairs from .520 x .620 to .620 x .710 in, up to 50 psi.[4] If your tubing is 0.63 to 0.70 in OD, Rain Bird's Easy-Fit compression coupling and tee are listed for that range, 0 to 60 psi.[6] Easy-Fit is not listed for .710 in tubing.
Picks that fit4 products
Orbit 67466 coupling for .620-.710 in OD. Raindrip S5600UB coupling for .520 x .620, .600 x .700 or .620 x .710 in tubing.
More on choosing
Rain Bird EFC25-1PS coupling or EFT25-1PS tee only for 0.63-0.70 in OD, not .710. Each listing is a single fitting. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
Choose the Orbit 67466 for the widest stated OD range
Orbit 67466 1/2 in universal drip coupling (0.620‑0.710 in OD)
Choose the Raindrip Smart Loc S5600UB when you know your ID x OD pair
Raindrip Smart Loc S5600UB universal coupling (0.620, 0.700 and 0.710 in OD)
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)
Raindrip also sells a Smart Loc tee, S5500UB. We found no verified Raindrip spec for the tee itself, so check that its listing states your tubing size before you order it.
Picks that fit1 product
Choose the S5500UB tee (1 piece) only if the listing states your tubing's ID and OD. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Raindrip.
Smart Loc tee, same three sizes
Raindrip Smart Loc S5500UB universal tee (0.620, 0.700 and 0.710 in OD)
Every page on mainline fittings
Guides
- Compression, barbed or locking-nut drip fittings: how each one grips
- Green, black or blue? DIG compression inserts by tubing OD
- Join .700 drip tubing to .620 or .710 tubing
- "Universal" drip fittings: the OD range behind NUTLOC, Smart Loc and Orbit
- Drip tubing end caps, figure-8 closures and flush points
- Repair split or punctured drip tubing
- Join metric 4/7 mm and 16 mm kit tubing to US parts
Tools
- Drip connection type finder: what meets directly and what needs an adapter
- Drip tubing size finder: which fittings list your OD
Connection types
Fitting lines
Key terms
Compression insert, universal fitting, coupling, reducing coupling, end closure, figure-8 end closure and push-to-connect fitting.
Everything in this topic
Guides
- Compression, barbed or locking-nut drip fittings: how each one gripsHelps you choose the fitting type that your tubing's documented size supports, and know whether you can take it apart later.
- Green, black or blue? DIG compression inserts by tubing ODHelps you read the insert color on a DIG compression fitting as a tubing OD, and not apply that code to other brands.
- Drip tubing end caps, figure-8 closures and flush pointsHelps you choose an end closure that fits your tubing and can be opened for flushing and draining.
- Join .700 drip tubing to .620 or .710 tubingHelps you pick a coupling that is listed for both of the tubing sizes you need to join.
- Repair split or punctured drip tubing: plug, splice or replaceHelps you decide between plugging and splicing a damaged drip line, and choose a coupling that fits it.
- "Universal" drip fittings: the OD range behind NUTLOC, Smart Loc and OrbitHelps you read the size range behind a "universal" drip fitting and check it against your tubing's OD.
Comparisons
- Orbit 67466 vs Raindrip Smart Loc vs Rain Bird Easy-Fit couplingHelps you choose the coupling whose maker-stated range covers your tubing's OD, then by pressure and removal.
Shortlists
- 1/2 in drip fittings with a stated OD rangeHelps you pick a 1/2 in coupling or tee whose maker-stated range includes your tubing's OD.
Tools
- Drip connection type finderTells you whether two drip parts can join directly or need an adapter, and which dimension to check.
Common questions
Which universal drip coupling fits .710 tubing?
Orbit lists the 67466 for .620-.710 in OD and Raindrip lists Smart Loc S5600UB for .620 x .710 in tubing. Rain Bird lists Easy-Fit for 0.63-0.70 in OD, so .710 in is outside its range. More in Orbit 67466 vs Raindrip Smart Loc vs Rain Bird Easy-Fit coupling
Which of these couplings fits Rain Bird T63 tubing?
T63 is 0.63 in OD. That is inside Orbit's .620-.710 in range and at the bottom of Easy-Fit's 0.63-0.70 in range. Raindrip lists .620 in OD, not 0.63, so ask Raindrip before using Smart Loc on T63. More in Orbit 67466 vs Raindrip Smart Loc vs Rain Bird Easy-Fit coupling
Which has the highest pressure rating?
Rain Bird lists Easy-Fit at 0 to 60 psi and Raindrip says Smart Loc S5600UB handles up to 50 psi. We found no pressure rating on Orbit's 67466 page. More in Orbit 67466 vs Raindrip Smart Loc vs Rain Bird Easy-Fit coupling
Can I take these couplings apart later?
Orbit says the 67466 is reusable: loosen the nut to remove the tubing. Raindrip and Rain Bird do not state reuse on the pages we read. More in Orbit 67466 vs Raindrip Smart Loc vs Rain Bird Easy-Fit coupling
Which is better, compression or barbed drip fittings?
Neither in general. A compression fitting is sized by the tube's outside diameter and a barbed insert by its inside diameter or a metric family, so choose the type your tubing's documented size supports. More in Compression, barbed or locking-nut drip fittings: how each one grips
What is a spin-lock drip fitting?
A fitting with a barb that goes inside the tube and a nut or collar that tightens over the outside. Raindrip's Smart Loc secures with a barb and twist-on nut, and Orbit's 67466 locks with a hand-twisted outer nut. More in Compression, barbed or locking-nut drip fittings: how each one grips
Are drip fittings reusable?
Only where the maker says so. Orbit says the 67466 coupling is reusable by loosening its nut, and Mister Landscaper calls its MLF locking-collar fittings reusable. More in Compression, barbed or locking-nut drip fittings: how each one grips
Can I use drip tape fittings on poly tubing?
Not Perma-Loc ones, according to Drip Depot, which says Perma-Loc fittings for drip tape and for poly tubing are not interchangeable. More in Compression, barbed or locking-nut drip fittings: how each one grips
Questions
What size fittings do I need for 1/2 inch drip tubing?
Fittings whose maker lists your tubing's OD. DIG's black-insert fittings are for .700 in OD and its blue-insert fittings for .710 in OD; Rain Bird's Easy-Fit is listed for 0.63-0.70 in OD. See how to measure drip tubing.[1][6]
Are universal drip fittings universal?
No. Each covers the range its maker states. Orbit's 67466 is listed for .620-.710 in OD, DIG's NUTLOC for .630-.710 in OD, and Rain Bird's Easy-Fit for 0.63-0.70 in OD.[5][3][6]
Can I reuse drip fittings?
Locking-nut fittings are made to come apart: Orbit says you loosen the 67466 nut to remove the tubing, and Mister Landscaper calls its MLF fittings reusable.[5][9]
What do the colors on compression fittings mean?
On DIG fittings, the insert color marks the tubing OD: green for .620-.630 in, black for .700 in and blue for .710 in. That mapping is DIG's; other makers may use other colors.[1]