... sealing ,light weighting ,easy to fix and maintain,also has long usage life .But please keep far away from sharp metal ... to avoid breaking of the ball.Flange Drilling: according requirement.Rubber: EPDM RubberFlanges: carton steelWorking Pressure: 16 bar-25barBurst Pressure: 48 ... Media: air, water, sea water, weak acid, oil, alkaline, etc high quality resistance rubber compensator