Direct-burial valve wire, 2-wire decoder cable, waterproof splices, grounding and submersible pump cable for irrigation control.
Wire gets the least attention at install and the most two seasons later, when a zone stops opening and nobody knows which conductor in the valve box it was. This page carries Paige direct-burial valve wire from 18 to 1/0 AWG, multi-conductor cable from 2 to 25 conductors, polyethylene wire for treated ground, armored wire for rodent ground, two-wire decoder cable, Toro communication cable, waterproof splices, grounding hardware and submersible pump cable.
ML Irrigation sells it wholesale from Fountain Inn, South Carolina to production nurseries, greenhouse operations and horticulture education programs in all 50 states. Use the guidance below to pick the type and gauge, then request a quote with your run lengths and valve count.
Single conductor, multi-conductor or decoder cable: which type fits the system?
Start with the controller. A conventional AC controller with a terminal per station needs a hot to each solenoid and a common back, which is what the valve wire here is built for. A two-wire decoder controller such as a Toro TDC, Rain Bird LXD or Hunter EZDS needs one twisted decoder path around the site instead. Ordinary valve wire will not do that job; the twist rate is what keeps noise off the path.
For conventional systems the choice is single conductor or multi-conductor. Paige single conductor Type UF runs from 18 to 1/0 AWG, solid copper through 8 AWG and stranded from 6 AWG up, in as many as 12 colors so zones stay identifiable years later. It suits short greenhouse runs, heavy commons and long pulls where each conductor is sized to its own load. Multi-conductor 18 AWG cable carries 2 to 25 conductors in one jacket, color-coded by count, and saves pulling a dozen separate wires down the same trench to a valve bank.
Three site conditions change the answer. Ground that takes fertilizer, herbicide, pesticide and fungicide season after season wants the polyethylene golf course wire, because PE resists the chemistry that degrades PVC. Beds with mice want armored wire on the main runs. A well pump wants submersible pump cable rated for continuous submersion, which valve wire is not. Toro satellite systems use shielded communication cable specified by pair count, and it is not interchangeable with valve wire either.
How do I size the gauge, and what does the site need to be?
Gauge is sized off run length and total solenoid load, not off habit. Voltage drop grows with distance and with the number of solenoids on the same conductor, and the symptom is a valve that will not pull in at the far end. 18 AWG covers a zone or two inside one house. 16 AWG is the step up when 18 is marginal, and 14 AWG is the common size for runs leaving the headhouse. 12 and 10 AWG reach distant blocks and carry several zones back on one common. From 6 AWG up the wire is stranded, for the longest runs and heaviest commons. The common carries every zone on it, so it is normally run heavier than the hots. If you want a second opinion on gauge, ask us with your run lengths and valve counts.
The site needs less than expected. Paige Type UF wire and the 18 AWG multi-conductor cable are direct burial, sun resistant and UL 1493 listed, with no conduit required and a 30 V maximum rating. What it does need is a filled splice at every joint and marking on every bundle. On heavily treated ground the PE golf wire is thinner walled and lighter than Type UF and carries a UL 1551 600 V listing as well as 1493. A two-wire decoder path also needs grounding at the intervals the controller maker specifies; a long conductor in open ground is what a lightning strike finds.
What goes wrong on real nurseries, and how the Paige lines differ
Wire causes a fair share of callbacks, and most are not the wire. They are the splice. A wire nut and tape in a valve box is a failure waiting for the first wet week; a silicone- or gel-filled splice rated for continuous submersion is not. The splice line includes Ideal WeatherProof and 3M direct-bury splices, gel-filled connectors, resin and epoxy kits and brass split bolts for 16 to 8 AWG. Re-enterable connectors earn their place on any joint you expect to open again.
The other mistakes repeat. Grounding gets skipped on a two-wire install, and one storm takes out a run of decoders. Ordinary wire gets substituted for decoder cable. Gauge gets picked from the shelf instead of from the run. Nobody marks the bundle, so every trip to the valve box costs an hour. Wire markers, tape and strippers sized for irrigation gauges are here for that reason.
Paige separates its lines by what the ground will do to them. Type UF single conductor (P7001D and P7002D) and P7183D multi-conductor are the PVC-insulated standard for clean soil. The P7079D golf course wire swaps PVC for polyethylene and is marked GOLF WIRE on the jacket. The P7167D and P7168D armored wire adds metallic armor for rodent ground. Communication and decoder cable are built shielded or twisted for signal, and the SP Flat Jacketed and SP Twisted pump cables are the only ones rated to hang in a well.
Frequently asked
When should I step up from 18 AWG valve wire?
When the run gets long enough, or the solenoid inrush high enough, that voltage drop starts dropping out valves at the far end. 18 AWG covers a zone or two inside one house; 16 AWG is the usual next step, and 14 AWG is the common gauge for runs leaving the headhouse. If you want a second opinion on gauge, ask us with your run lengths and valve counts.
Does direct-burial valve wire need conduit?
Paige Type UF valve wire and the 18 AWG multi-conductor cable are rated for direct burial, sun resistant and UL 1493 listed, so no conduit is required. They are 30 V maximum control wire, not power cable. What they do need is a filled, submersion-rated splice at every joint and armored wire where rodents chew, because irrigation wiring fails at the connections far more often than along the run.
Can I run a two-wire decoder controller on regular valve wire?
No. Decoder controllers such as Toro TDC, Rain Bird LXD and Hunter EZDS need twisted 2-wire decoder cable; the twist rate keeps noise off the path, and ordinary wire is not a substitute. Plan grounding at the intervals the controller maker specifies at the same time, since a long path in open ground is what a lightning strike finds.
Which wire goes in ground that gets sprayed and fertilized all season?
The Paige polyethylene golf course wire, in 14, 12 or 10 AWG. PE insulation resists the fertilizer, herbicide, pesticide and fungicide chemistry that degrades PVC over time, and the jacket is marked GOLF WIRE so it is identifiable later. It is unnecessary on clean ground and worth it on a heavily treated one.
Who does ML Irrigation sell wire and cable to?
ML Irrigation sells wholesale to production nurseries, greenhouse operations and horticulture education programs, and ships from Fountain Inn, South Carolina to growers in all 50 states. Paige multi-conductor counts not listed on the page can be quoted as well. Request a quote with gauge, conductor count and footage, or contact us if you would rather talk the layout through first.
