When looking at the P-F reliability curve, there are two main categories of maintenance reliability action where resources may be focused: the P-F region and the I-P region.
The P-F region (see Figure 1) is the portion that typically receives most of the attention. Since the equipment defect or failure has already begun, this region is about detecting and predicting equipment failure modes so repairs can be made in a planned manner. Continue reading
In the June/July 2016 Uptime article, “Condition Monitoring and MEMS Accelerometers: What You Need to Know,” several attributes of microelectromechanical system (MEMS) accelerometers were presented that make the technology compelling for condition monitoring applications. This article reviews data demonstrating the state of MEMS technology development and performance levels by comparing it to a commercially available piezoelectric (PZT) condition monitoring accelerometer.
Interpreting the vibration signature of plant equipment.
Vibration analysis, properly done, allows the user to evaluate the condition of equipment and avoid failures. Maintenance personnel can minimize unplanned downtime by scheduling needed repairs during normal maintenance shutdowns. How can you interpret — at a glance — the comprehensive spectrum information available? In layman’s terms, here is how to interpret the vibration signature of rotating equipment. You can learn to recognize misalignment, a defective bearing, bent or loose parts — and tell them apart.
Plain and simple: there’s a lot that goes into a preventative maintenance program for hydraulic systems. While it’s a discipline that’s very basic and uncomplicated when you boil it down, there are many tests that need to be performed and plenty of steps where something can be done incorrectly, so it’s critical to the health of your machine that all are done regularly and properly. In order to do this, it’s important that both the system and hydraulic fluid are taken care of, as your fluid and systems are completely interdependent.
by Jeff Owens, Advanced Technology Services
Lean out your maintenance process and deliver cost savings and greater efficiency.
Manufacturers worldwide know that Lean maintenance practices cut costs and improve production by minimizing downtime. But the reality is that for many U.S. manufacturers, up to 90% of the maintenance they perform is conducted on a reactive rather than proactive basis. Some blame the age of their equipment, the absence of spare parts and the rapid pace of manufacturing.
For purposes of this article, reactive maintenance is any planned or unplanned work with a priority designation of emergency or urgent, therefore requiring immediate attention. Plus, there could be work of any priority that is “worked on” outside of the weekly schedule, which this author calls “self-inflicted reactive maintenance.”
Research currently being carried out by the Center for Risk and Reliability, University of Maryland 1, and funded by the U.S. Navy is aimed at quantifying reliability in scientific terms. The present study “relies on a science-based explanation of damage as the source of material failure and develops an alternative approach to reliability assessment based on the second law of thermodynamics.” Current reliability calculations are predisposed to a single failure mode or mechanism and assume a constant failure rate, while this research implies that reliability is a function of the level of damage a system can sustain, with the operational environment, operating conditions and operational envelope determining the rate of damage growth.
Monitoring the condition of large industrial machinery provides long term benefits in terms of lower production cost, reduced equipment down time, improved reliability, and increased safety. Industrial manufacturers face a constant battle in keeping production equipment operational. Ensuring that all of the key elements of the process are in good working order allows them to standardize costs, ensure consistent output of the end product, and reduce the risk of delivery delay to their customers.