Page 76 - Reciprocating Compressors Operation Maintenance
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Design and Materials for Reciprocating Compressor Components 63
Tandem Piston Rod. This is a piston rod on which two or more pis-
tons are mounted in tandem. This is used where loading is low so that the
combined loading does not exceed the allowable frame load. fHgure 2-22
shows a tandem rod in a tandem cylinder compressor.
Piston Rod for Truncated Cylinder. This is a special configuration
which accommodates the truncated cylinders illustrated in Figure 2-23. A
truncated, or stepped, piston compressor cylinder is designed with differ-
ent bore sizes for head end and crank end. Two stages of compression
can be handled—each stage single-acting. This type of compressor cylin-
der is custom-designed for each application and is typically available in
forged steel and fabricated steel. Normally the void space between the
FIGURE 2-23. Truncated cylinders (Source: Pennsylvania Process Compres-
sors, Boston, Pennsylvania).
FIGURE 2-24. Compressor cylinder with tail rod arrangement (Source:
Dresser-Rand, Painted Post, New York).
