... DN150 to DN500 4.Model:200--500 Control valve1.PictureNo.1 Diaphragm ValveNo.2--Rotary Valve with Rotating Cleaing BladeNo.3NO.4N0 ... from DN150 to DN500 with compact structure, dust proof and water proof, strict airproof, easy to operate, open and close ... applied to building material, chemical, food, metallurgy, power industry, can control powder or granule material to charge or discharge.3.Warranty ...