Polyethylene (Black Plastic) Pipe

Common terminology for this pipe is Poly pipe.

I don’t see this pipe much anymore in sprinkler repairs. It is usually installed in yards of older homes from the 1950’s – 1970’s. Poly pipe has low pressure ratings around 125 psi compared to PVC pipe of the same size which is rated around 450 psi. Plastic, cast brass and forged steel inserts fittings are used to make connections to the pipe. Then a hose clamp is tightened on the insert fitting to keep the connection from leaking. Even through the clamps are stainless steel, whenever I dig up a connection the clamps are always rusted and often times rusted to the point that they are not providing any holding strength to the fitting.

You can still buy the pipe and fittings at home improvement and sprinkler supply stores.

When installing these fittings, I find that dish soap or some other type of lubricant is helpful in inserting the fittings into the pipe. I also use a rubber mallet to tap the insert fitting into the pipe. The rubber mallet keeps the fitting from being damaged when tapping it into the pipe.

If you have this type of pipe in your yard you will probably at some point need to upgrade the piping to something else like PVC pipe. What I have noticed is that over time the pipe becomes brittle and will begin leaking in multiple locations.

Pros – None. I can’t think of any advantages this pipe would have over any other type of sprinkler pipe.

Cons – Hard to repair, time consuming to install fittings, and has a low pressure rating. Miserable!