Washout – Water runs down the rim holes which washes the side walls, floods the sump (bowl area) and a water exchange is made exiting through a bottom outlet. This method is like a dilution process.
Siphon Jet – A jet hole is on the inlet of the trapway. When flushed, water is fed into the jet creating a stream that assists in pulling the water out of the urinal. With this method, the entire amount of liquid is displaced when flushed and siphon jet action will flush away most debris (cigarettes, gum, etc.).
Blowout – A hole is on the inlet of the trapway. This is the most aggressive flush, and as a result is the noisiest of the three options. With this method, the entire amount of liquid is displaced when flushed. Since it a very aggressive flush, it will remove all the contents including items like cigarette butts. The high velocity jet action with larger trapway assures better drainline carryout and is recommended for stadium and other high usage commercial applications.