Plast-O-Matic Valves offers a low-cost flow control valves in natural polypropylene, PVC, and other rugged thermoplastics to maintain a constant, pre-determined flow in a piping system. Flowrates range from 1/4 gallon per minute to 120 GPM and can be maintained to within 10 percent accuracy with varying inlet pressures from 15 to 120 PSI. Ideal for highly corrosive or ultra-pure liquids, the valve is pre-set and tamper-proof and requires no electrical connection or electronic control.