Fengyu's vacuumzing and refilling device is used for SF6 electrtic device to vacuum and refill gas. specification: VCH-14\28\54\252\500vacuum pump: 14M3, 28M3, 54M3VCH series for vacuumzing and refilling of gas, movable, with flexible pipe and joints DN8 and DN20, max vacuum pressure less than 10Pa.