Flomatic® Flo-Trol® automatic flow control valves are designed to give constant flow over a wide pressure range. The valve design has no moving part; rather, a self-cleaning flexible orifice that varies in size with applied pressure so that a constant flow rate is maintained. Flow rates are maintained to within ±15% between 15 and 125 PSI. Each Flo-Trol® valve is laser engraved with flow rate, size, and certification. In addition, each Flo-Trol® valve comes sealed, color-coded, and labeled.