Modern standards require frame sensors and more
This paper reviews and discusses the machinery protection philosophy for reciprocating compressors that once was state of the art, and examines how technology, as well as applicable standards, have evolved since the 1970s, a time when many refineries have been built with a large fleet of reciprocating compressors installed.
For decades, reciprocating compressors did not enjoy the high-priority monitoring given to centrifugal machines. The reasons why are partially based on the higher number of centrifugal machines in comparison to reciprocating compressors, and operators just did not fear severe damages due to the lower kinetic energy of these comparably slow-running machines.
However, they show the highest number of damages while being process-critical at the same time. Although this is a crucial combination, insufficient protection and condition monitoring principles are still being applied on some reciprocating machinery.
At all times, operators, engineering procurement and construction companies (EPCs) and original equipment manufacturers (OEMs) have followed the existing, applicable guidelines and standards during the final engineering stage. Those standards were valid at the time of construction, and to a large extent are still valid today. However, upon reviewing the age of the reciprocating compressor population, one will recognize that, in many cases, these large, critical ma¬chines have never been replaced and they have been in operation since their initial startup date many decades ago.
To understand why, even after numerous catastrophic failures, we still find inadequate machinery protection on many of these machines, a view into the history of applicable standards can help to lift the fog.
American Petroleum Institute (API)
The American Petroleum Institute (API) has always been one of the leading organizations in compiling information about available and proven monitoring technologies for critical machinery and transforming them into standards that have become widely used as guiding standards. It is remarkable that the first revision of the widely known API Standard 670 was released in 1976. It was named “Non-contacting Vibration and Axial Position Monitoring System,” a standard focused on the application of proximity sensor-based machinery monitoring. The second revision of the same standard was released in 1986.
As a consequence of evolving vibration-monitoring technology, API has followed up with a parallel standard covering vibration technology within the 1981-released API 678 “Accelerometer-Based Vibration Monitoring System — 1st Edition.”