Mazzei fertilizer injectors are commercial-grade, Venturi style injectors with no moving parts to wear out or break down. The Mazzei works by suction, and can draw liquid fertilizer from virtually any container. It can be plumbed on a bypass for less restriction (the preferred method), or directly into a main water line. You will need to experiment to get the dosages required, but once operating, the Mazzei is incredibly reliable and relatively maintenance free.
Three parts are required to make a complete unit: an injector, a bypass and a suction assembly. The bypass and suction assembly are sold separately.
It is important to choose the model size carefully based on the water usage of the irrigation system. Select the injector that matches the flow rate (GPH) that your irrigation system uses. An oversized injector will not draw the fertilizer at all; an undersized injector will restrict the flow of the system. If in doubt always choose a smaller size and install on a bypass assembly. This allows you to adjust the Mazzei's flow with less restriction.
Rebuild kits are available for all Mazzei injectors.