... operated cast iron wafer butterfly valve for cement Flange Drilling:Universal flange drilling able to comply with:DIN PN6/10/16, ... valve torque.2. Grooved sleeve design to achieve stable positioning.3. Simple construction, small in size, Easy disassembling, installation ... flow rate and low flow resistance.6. Suitable medium: water, sewage, sea water, air, steam, food, medicament, oils, acids, alkalis ...