Lubricated air compressors are made of cast Iron twin cylinder oil lubricated pump for long life and quiet operation. 6 HP 240v motor provides more hp than 115 v motors which is the unique unit for those who need lots of portable air power. With air flow usually found in big stationary compressors, this unit offers enough power to attack big projects. The twin cylinder, oil lubricated, cast iron single stage pump runs quieter so the compressor can be used in the same area that the job is taking place. Solid cast iron units are up to 35% quieter than aluminum units with cast iron cylinder sleeves, and dramatically quieter than direct drive aluminum compressors. Oil lubricated air compressors are integrally mounted on air receivers to offer further ease of installation and versatility. Tank mounted units should always be used when an accelerator is required on the sprinkler system. Multiple dry valves may be supplied from a single tank mounted air compressor when using an UL / FM approved air maintenance device on each individual system.