Gas Compression Calculator

Required Horsepower is driven by the Compression Ratio, and raising Discharge Pressure while holding Suction Pressure fixed directly raises that ratio. A higher ratio means each unit of gas must be compressed through a larger pressure rise, which takes more work -- so Required Horsepower increases whenever Discharge Pressure goes up, all else held equal.

Yes. Raising Suction Pressure while holding Discharge Pressure fixed lowers the Compression Ratio, since the ratio is Discharge Pressure divided by Suction Pressure. A smaller ratio means less work is needed to reach the same discharge pressure, so Required Horsepower falls as Suction Pressure rises -- one reason low-pressure gathering systems often need disproportionately large compressors.

Compressor Efficiency appears as a straight divisor in the horsepower formula: a lower efficiency means more of the input power is lost to mechanical friction and internal losses rather than doing useful compression work, so the required input horsepower rises accordingly. Raising Compressor Efficiency always lowers Required Horsepower for the same compression job.

Reciprocating compressors are conventionally kept below about a 4:1 pressure ratio per stage, because a single large ratio drives discharge temperature and valve loading too high for reliable operation. When the overall Compression Ratio you enter exceeds that, the calculator splits it evenly across enough stages to keep each stage's ratio under the limit, shown as Ratio per Stage.

It estimates how hot the gas gets after being adiabatically compressed through one stage at the calculated Ratio per Stage, starting from your Suction Temperature. Raising Suction Temperature raises Discharge Temperature one-for-one along the same curve, since the calculation adds the same temperature rise on top of whatever temperature the gas started at -- a high result is a signal that intercooling between stages may be needed to protect compressor valves and seals.