Irritrol 700 Series Valves Irritrol 700 Series Valves feature a Unique straight-through flow path, Slow closing design, Glass-reinforced nylon, stainless steel and brass construction, High and low flow operation and a Self-flushing, 150-mesh, stainless steel filter screen on 1, 1 1/2 and 2 inch models. An extremely low-friction design makes this valve ideal for low-pressure and multiple-head applications.