Page 64 - Reciprocating Compressors Operation Maintenance

Design and Materials for Reciprocating Compressor Components 51

All cylinders can be modified to provide capacity control or to provide
openings for clearance pockets and internal plug unloaders.

Cylinder Materials

Cylinders are made of material selected for the particular pressure and
gas being handled. Variables which must be considered in the selection
of materials include bore diameter, pressure differential, and the type of
gas to be handled.

Low and Medium Pressure Cylinders

These are normally made of cast iron but are also available in nodular
iron or cast steel depending on application. The cylinder shown in Figure
2-7 has a solid bore, but in most designs the cylinders may be furnished
with sleeves or liners. These cylinders normally have generous water
cooling around the bore and in both heads. Pressures can be up to 2000
psi depending on the bore diameter.

Medium to High Pressure Cylinders

This cylinder, Figure 2-8, has heavier wall sections and smaller bores
than the cylinder shown in Figure 2-7. The material used would normally
be nodular iron, but steel has been used in the past. Cooling and control

FIGURE 2-8. Medium- to high-pressure compressor cylinder (Source: Dress-
er-Rand, Painted Post, New York).