... on evenness, rotation: 5-30 r/min, stepless variable speed1. Arch single workpiece disc, maximally meeting customers’ requirement ... on evenness, rotation: 530r/min, stepless variable speed2. Arch three-workpiece disc, planetary revolution and autorotation, ... on production amount, rotation: 5-30r/min, stepless variable speedVacuum systemDiffusion pump KT-600, Roots pump ZJ-300, ...