Ingersol-Rand Straight-Line, Horizontal Heavy-Duty Compressor ES, ER, FR and FS Manual Ingersol-Rand Straight-Line, Horizontal Heavy-Duty Compressor (Probably marked: ES, ER, FR and FS). Operator's Instruction and Maintenance Instructions. Manufacturers: Ingersoll-Rand Rand Models: ER ES FR FS Contents: Operators Manual Maintenance Manual