Reciprocating Compressor Condition Monitoring A Straightforward Guide to Monitoring & Diagnostics
Experts worldwide agree – the only way to ensure safe, reliable, efficient, economical operation of reciprocating compressors is to monitor them continuously and take appropriate action based on the information the monitoring systems provide.
That simple objective, however, is difficult to put into practice. The variety of instruments, systems, and methodologies for machine monitoring and diagnostics can be perplexing. Descriptions and claims are sometimes similar, sometimes conflicting, and almost always confusing.
To help provide clarity for your decision process, we offer this plain-language guide to system selection. It lists the essential capabilities a system should have and explains why those capabilities are needed.
This is the culmination of more than 20 years of experience in developing and applying monitoring and diagnostics systems around the world. We sincerely hope our depth of experience will be of assistance to you as you evaluate and implement a system for your operation.
Why It Matters: Systems should be scalable in two ways. First, they should be functionally scalable, allowing new or additional capabilities, such as measuring loops, to be added to an installed system without inordinate cost or difficulty. Second, systems should be scalable in magnitude. In other words, a system should offer a means to expand monitoring to additional machines.
Scalability allows you to take advantage of new developments and keep your system state-of-the-art. As your needs change and your experience with a system grows, you will likely wish to extend coverage to other machines. A truly scalable system provides a simple, cost-efficient pathway for growth.
The Best Approach
Monitoring systems should consist of modules that fit together as building blocks to form a system that meets your individual monitoring requirements. To add capabilities or coverage for other machines, you simply “plug in” new modules. This allows you to focus only on those capabilities you really need (monitoring “bad actors”) in the beginning and then grow as necessary. In other words, think big – start small. Functional scalability is dependant upon your vendor’s commitment to continual system improvements. This commitment is demonstrated in the frequency of system enhancements such as software updates. Your vendor should invest in ongoing research and development to make regular system updates and upgrades available.
Why It Matters: Detecting the presence of an anomalyis one thing. Defining and pinpointing it is another. Your monitoring system should not only warn you about problems, but also provide an accurate diagnosis with specific component identification, location, and indication of the extent of damage. Armed with this information, you can make wellfounded decisions about the maintenance procedures you need to take and when you need to take them.
The Best Approach
There are no shortcuts in developing a system for automated diagnoses. An accurate, detailed understanding of a problem is acquired only through extensive experience in machinery monitoring. The reason is clear: when a monitoring system detects an anomaly, it compares its characteristics with an integrated, experience-based failure mode database. A match of this anomaly with a real-life failure pattern leads to an accurate, reliable diagnosis. Equally valuable is the message your system communicates to you. In the event of a positive failure pattern match, alarm, or shutdown, you need answers. Modern systems should provide clear communication about the cause for the alarm. For example, the message “Discharge valve leakage, cylinder 2, match 89%” gives the cause of the problem, location of the problem, and confidence in the diagnosis. Two additional considerations: first, be wary of systems that claim “expert diagnostics routines,” but lack dedicated recip know-how. Precise diagnoses cannot be performed without powerful and intelligent algorithms. Second, think about the capabilities of even the most sophisticated diagnostic technologies and the messages they generate. Is it realistic and reliable for a system to issue an impending damage report that identifies a screw (with its part number) that has to be tightened?
Why It Matters: The days of time-based maintenance are over. State-of-the-art monitoring technology gives you the ability to apply condition-based maintenance, reliably detecting developing failures and intervening before breakdowns have an opportunity to occur. Early failure detection prevents machine damage, enhances safety, avoids unplanned machinery shutdowns, and reduces costs of operation. Success depends on the ability to accurately identify mechanical defects at an early stage – regardless of operating conditions – without issuing false alarms.
The Best Approach
There are no shortcuts in developing a system for automated diagnoses. An accurate, detailed understanding of a problem is acquired o…