... 253.Material: Cast Iron,Carbon steel,Stainless Steel4.Operation: Hand wheel, gear, square head.5.Standard: GB,DIN, ... check valves,safety valves,ball valves,butterfly valves,diaphragm valves,mud valve ect.And it has complete inspection equipment, such ... Air driving,Take pneumatically manually,Hydrodynamic driving,Electric driving(Hand wheel driving omitted),Explosion electric driving.2.Connecting type: ...