High speed exhaust valve

Air vlaves are applied an the water pipelines as the eaulpment to exclude the gas inoipelines. it enhances the efliclency ofwater transcort and protectthe pipelines iromtranstoration and brake, When the pipeline under neoative pessure, this yalve wll suetiatair aulormalically lo pravent the pipeline broken, This yalve has bia gas displacementfodouble airvenits, it owns maintenance valve, close it when repair then it can be on-lineoverhaul.