Beginners Guide: ¼” Distribution Tubing For Drip Irrigation

The most creative landscapers and irrigation designers I know are drawn to drip and micro irrigation because of the flexibility it provides to create beautiful water efficient landscapes. There are a multitude of "right" ways to irrigate with drip and micro irrigation. This creates opportunities for creativity when designing drip irrigation.When selecting ¼" distribution tubing (also referred to as spaghetti tubing) there is not a lot of decision making involved. You only need to make one decision, vinyl or polyethylene. ¼" distribution tubing is generally the tubing that delivers water to drippers, sprayers, or shrubblers. The drip irrigation industry has yet to establish industry standards for tubing. As a result, with ½" tubing the inside and outside diameters are different from manufacture to manufacture and sometimes fittings don't work properly. With ½" and above tubing you should be using the same manufacture for your tubing and your fittings to make sure the size is correct. There is a size difference in ¼" tubing. Typically vinyl has an inside diameter of .156" and an outside diameter of .245" while polyethylene has an inside diameter of .17" and an outside diameter of .25". However, all the ¼" fittings should work with vinyl or poly tubing.

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Which is best poly or vinyl distribution tubing?

Polyethylene tubing

The one thing you need to remember is in warm climates polyethylene tubing is the only way to go. Polyethylene (poly for short) tubing feels stiff and might feel like it will crack easily. But that is not the case. It withstands the sun very well and does not expand in heat. So if your tubing is exposed to the sun everyday year after year poly tubing resists expanding and won't pop off fittings as easily as vinyl. The contractors I know in Southern California, Arizona, Nevada won't use anything other than poly.

Vinyl tubing

Vinyl tubing will feel very flexible and soft when you pick it up. The flexibility is the main reason I hear contractors use it. It can make tighter turns without kinking. The vinyl tubing and the poly tubing price tends to be very close, so I don't think price is going to be a reason to use one over the other.

The maximum run length for ¼" distribution tubing is 30 feet and 30 gph. This doesn't mean you can't run them longer, but when you do you will have very inconsistent water flow and your plants will suffer. Remember the 30 by 30 rule and you will have successful installations. You can also bury this tubing to eliminate a messy tubing look in your landscape.

Hopefully some of the mystery has been taken out of ¼" distribution tubing and you now have a better idea of how and when to use poly or vinyl. Distribution tubing gives us the ability to put water exactly where we want it to save water, improve plant health, cut down on weeds, and have longer lasting blooms. I'd love to hear about the creative ways you are using ¼" distribution tubing.

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