June 2012 Vol. 239 No. 6

Features

Bypass Method For Recip Compressor Capacity Control

This article considers the bypass method for capacity control in reciprocating compressors. The method is the oldest in controlling outlet capacity, which is used in all types of compressors for turndown capacity between 100% and zero. The reciprocating compressor is a positive displacement machine. During normal operation, it takes in a quantity of gas from its suction line and compresses the gas as required to move it through its discharge line. Unlike centrifugal compressors, reciprocating compressors cannot self-regulate their capacity against a given discharge pressure. In fact, it keeps compressing without limitation unless we specify the range of work, and that capacity