... r/min),high efficiency,small volume,light weight,and compact structure.2.2Air cooling structure,pressure rise 98Kpa, ... ensures reliable running with low noise under the high pressure condition.2.4Precision harden-teeth-surface helical timing ... reliable locating,balances running with low noise,high rigidity,and long life.2.5By adopting the SKF ... to ask me. oxygen making use high pressure roots blowers