System Components and Materials
Heads, pipe, fittings, pumps, and filters
Heads fall into three families: sprays (fixed arc, high precipitation, short radius), rotors (gear-driven, low precipitation, long throw), and drip/micro (emitters, lowest precipitation, best for beds and wind). Nozzle choice sets precipitation rate; a mismatched nozzle on the same zone creates stripes. Use check valves on heads at the low point of a slope to stop drainage between cycles.
Pipe: PVC Schedule 40 is stronger than Class 200 at the same diameter, so use Schedule 40 for mainlines and high-pressure work; poly is flexible and freeze tolerant but needs insert fittings and clamps. Match solvent-weld cure times to temperature - joints forced apart too soon leak.
Details matter: swing joints or funny pipe let heads be set to grade and survive impact; a wye strainer protects drip and small nozzles; a pressure regulator holds drip laterals near 25–30 psi.
Pumps: centrifugal for surface suction (needs a foot valve and priming), submersible for wells (needs a check valve and proper setting depth). Size the pump to the system curve - a pump running far off its curve wastes energy and short-cycles.
Rule of thumb: never reduce pipe size below the largest fitting downstream, and never install a drip zone without both a filter and a regulator.