... Nominal Diameter DN: 50-700mm(2-28aa) CST42Y Automatic Re-Circulating CCirculatin Nominal Pressure PN: 1.6 ... DN: 50-700mm(2-28") CST42Y Automatic Re-Circulating Control Valve (reflux valve) is installed at the outlet of ... backflow of medium through the pump outlet. The valve is widely used in industrial fields, such ... , Monel, 316,310,304,WC6 and etc. Automatic Recirculation Control Valve (Return Valve)