Compressors are intolerant to liquids. In reciprocating compressors with inherently large volumetric displacement rates, all modes of liquid ingestion pose a serious problem and can even result in catastrophic failures. This paper describes a simple method of estimating the cylinder pressure and "rod load" (force on the crosshead pin, in compressor terminology) in a double-acting reciprocating compressor The results indicated that even with moderate volume of liquid present inside the cylinder the pressure could reach values as high as four to five times its normal value with a correspondingly higher rod load.