Many LPG systems (propane and butane) as well as pipeline systems for agricultural ammonia often do not provide ideal Net Positive Suction Head (NPSH) conditions. As a result, pumps frequently experience increased maintenance requirements.

Piston compressors, on the other hand, are operated solely with gases or vapors, so poor NPSH conditions do not affect their performance. Numerous pressurized LPG and ammonia vessels—such as tank cars or buried tanks—are equipped with top withdrawal connections. For liquid transfer in such applications, a piston compressor provides the ideal solution.

Most vertical LPG piston compressors from Corken feature single rod seals and are not designed for oil-free gas compression. The only exception is the CORKEN D891 model, which has two sets of seals (a V-ring seal and a segmented seal) but still does not operate oil-free.

Single-seal, non-oil-free compressors are typically used in non-corrosive and non-toxic applications where oil-free operation and leak containment are not critical. Typical applications include propane, butane, agricultural ammonia, and natural gas.