Plast-O-Matic Valvesoffers a low-cost flow control valves in natural polypropylene, PVC, andother rugged thermoplastics to maintain a constant, pre-determined flowin a piping system. Flowrates range from 1/4 gallon per minute to 120GPM and can be maintained to within 10 percent accuracy with varyinginlet pressures from 15 to 120 PSI. Ideal for highly corrosive orultra-pure liquids, the valve is pre-set and tamper-proof and requiresno electrical connection or electronic control.