Redoing a Sprinkler System

Dig up the old sprinkler system with a shovel or a trench digger. Use the pipe cutters to remove the old system. Cut the system all the way down to either the irrigation shut-off valve or the valve manifold, depending on the system. Leave about 3 inches of pipe coming from the irrigation shut-off valve or valve manifold.

Lay the parts of the new system according to plan beside the trenches. Parts might include swing pipe assemblies, sprinklers, pipes and fittings.

Wipe PVC primer and glue onto the inside of a connector fitting. Insert the connector fitting onto the end of the 3-inch pipe extension coming from the shut-off valve or the valve manifold. Hold the fitting in place for 15 seconds to allow time for the glue to dry.

Sand down the ends of the PVC pipe sections near the trenches. The pipe ends should be free of rough spots to ensure a proper connection to the fittings.

Wipe PVC primer and PVC glue on the ends of the first pipe leading from the shut-off valve or valve manifold. Insert the pipe into the connector fitting and twist it a half turn to settle it. Hold the pipe in place for 15 seconds. Repeat this process, until all fittings and pipes are connected together in the trenches according to plan.

Wrap Teflon tape around the threads of each swing pipe assembly in the direction of the threads. Twist the end of the swing pipe assembly into the T-fittings where you plan to insert sprinklers. Tighten the swing pipe assembly by hand.

Wrap Teflon tape around the threads of each sprinkler housing in the direction of the threads. Twist the bottom of the sprinkler housing onto the open end of the swing pipe assembly and tighten it by hand.

Cover the trenches with dirt. Confirm that each sprinkler is buried straight up in the ground and that the spray head barely breaks the surface.