Nash Liquid Ring Vacuum Pump. Model: SC3/7. S/N: 95D0435. Capacity: 350cfm of vacuum at a rate of 25 in. Hg., 240 cfm vacuum at a rate of 26 in. Hg. @ 1600 rpm. HP can be doubled, but capacity will be lower. Material of construction: ductile iron. As there is a reduction in humidity there is a reduction in vacuum that the pump will produce at a lower vacuum rate. Input rpm: 1170. Inlets: (1) 4 in. L x 4 in. W suction port with round flange. Outlets: (1) 3 in. dia. discharge. Overall dimensions: 35 in. L x 17 in. W x 20-1/2 in. H.(ACN66).