Reciprocating compressors are often used to handle very dirty and corrosive gases that have a negative impact on component lifetime and affect on the plant productivity. Due to this fact there are several ways to handle this problem, a few plants are using a identic machine as backup and in case of failure they are using the twin machine to keep the process running. But maybe this is not the best way. Efficient plants are asking for a condition monitoring system, this is where PROGNOST Systems comes to the play. A installation of a condition monitoring system like PROGNOST®-NT brings several benefits to the operator. Starting at the maintenance planning because he sees the development of his wearing parts and can configure warning thresholds. Early failure detection would be another very important point because in case of a emerging failure the system can notify him at an early stage. Beside some others there is the machine protection which can shutdown the machine in case of a critical failure to protect the machine and the process for consequential damages. This are only a few reasons why Petrobras (Petróleo Brasileiro S.A.) asked PROGNOST Systems to install its PROGNOST®-NT system on two Mannesmann Demag reciprocating compressors.


Compressors in service

The compressor duty is to compress the excess gas derived from pyrolysis extraction from shale. The plant is equipped with two Mannesmann Demag compressors, C-24101 A/B type 23B4G3/17. These are four-throw, balanced-opposed, reciprocating compressors with lubricated cylinders…


Problem description

The main problems are caused by the deterioration of the sealing elements (packing leakages) and consequent H2S attack on the internal compressor parts. These leakages led to possible condensate ingestion, and probable frequent condensate fog ingestion, as well as capacity loss because of valve obstruction….

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Condition Monitoring System

In 2005, PROGNOST presented its PROGNOST®-NT monitoring system expressly tailored for reciprocating compressor diagnostics. At São Mateus do Sul, the equipment operators had no experience in monitoring this type of machine. They only had a Monitoring system installed on an old 9.4 hp (7MW) Sulzer axial compressor installed in 1984, which allowed them to perform predictive maintenance …