... "-13"control valve 2,DN: DN15-DN200 3,Materials:ceramic 4,Certificates:ISO9001 Ceramic water level control valve Standards: 1,Material: lining ... :1, The parts contacting with the media are made of ceramic material, whose chemical stability and hardness (Rockwell hardness HRC90) ... , so the ball has high roundness, good surface quality, good sealing property. 4, The lifetime is two to four times longer ...