Inserting lengths of 1/4- or 1/8-inch vinyl tubing as feeder line into 1/2-inch poly pipe is no more complicated than inserting a drip emitter. Just cut appropriate lengths of vinyl tubing with pruning shears or a knife, then punch a hole in the poly header pipe with a hole punch. Insert a barbed connector into the hole, then insert the other end of the barbed connector into the length of vinyl tubing. Where two sections of vinyl tubing must be attached at the same spot, use a barbed tee connector. If the vinyl tubing is too stiff, soak it in warm water before use. Do not use glue, oil, or lubricants to assemble the parts.
Each section of vinyl tubing can be connected to a single drip emitter or a series of in-line drip emitters. The ordinary drip emitter is simply inserted at the end of the section of tubing. The emitter should be held off the ground with a stake to keep it from clogging. In-line emitters are inserted by cutting the tubing at the appropriate spot, inserting the emitter, and pushing the tubing back into place around it.
Any section of tubing that does not end in a drip emitter should be plugged with a tube end clamp, which is used in much the same fashion as a figure-8 end clamp. Like all pipe, vinyl tubing must be flushed before installing end caps or terminal emitters.
To water trees or shrubs, space in-line drip emitters evenly along the line within the canopy area. No more than 50 feet of 1/4-inch tubing can be used in one circuit and no more than 25 feet as lateral line. (Use 1/4-inch tubing for only very short runs.) Likewise, vinyl tubing will support only a relatively small number of emitters — a total 15 gph. You could thus incorporate up to thirty 1/2-gph emitters or fifteen 1-gph emitters per circuit.
It is all to easy to accidentally punch a hole in the wrong section of pipe or, after testing the circuits, to find one section that has too many emitters. This is easily corrected by pulling out the offending emitters and filling in the holes with hole plugs, often called “goof plugs.” Always have a few on hand when working with a hole punch.
Later, when tending the system, you will add and remove emitters on a regular basis, as plants are moved or die, or you decide a plant needs more or fewer emitters. Use goof plugs to plug the holes where you remove emitters.