Preventive Maintenance

Preventive Maintenance

Why Oil Goes Bad

I decided to write on this topic because I continually hear people say that oil doesn’t go bad, it just gets dirty. This implies that if you keep the oil clean, it will last forever. This is not true. I am frequently dismayed to see how many people simply don’t change the oil in certain machines. In general, all in-service lubricants will fail at some point.

See More
Preventive Maintenance

Why You Should Avoid Using Oil Funnels

“I have heard many different opinions as to whether funnels should be used for topping off an oil reservoir. Can you explain why funnels should or should not be used?” Across industry, it seems that if you are filling a machine or topping it off with oil, you will need to transfer the lubricant from a large container through a small fill port at the top of the machine. A funnel is designed to make this opening wider for adding oil. While funnels can make this task easier, they are not recommended because of their potential to introduce contaminants into the lubricant.

See More
Preventive Maintenance

An Introduction to Machine Vibration

Vibration in industrial equipment can be both a sign and a source of trouble. Other times, vibration just “goes with the territory” as a normal part of machine operation, and should not cause undue concern. But how can the plant maintenance professional tell the difference between acceptable, normal vibration and the kind of vibration that requires immediate attention to service or replace troubled equipment?

See More
Preventive Maintenance

From Screwdrivers to Testers: Vibration Testing and Analysis Comes of Age

Most machines have rotating parts and those rotating parts vibrate. Measuring how and how much those parts vibrate can tell you a lot about the health of a machine. Whether it’s the rumble of worn bearings or the shaking, shimmying, or thumping of loose, misaligned, or unbalanced parts, machines have a tale to tell those who are willing and able to listen.

See More
Preventive Maintenance

Acceleration Enveloping: Opening the Envelope on Bearing Vibration

A sophisticated signal processing technique can help to pinpoint bearing failure at an early stage. Chris Hansford, Managing Director at Hansford Sensors, explains. Experienced operators can often tell if a machine is not working properly, on the basis that is does not ‘sound right’. The same principle can be applied – using modern electronics – to identify the exact cause of the problem.

See More
Preventive Maintenance

Normalization of Deviance and the Perception of Defects

Ever walk into a room, look around and conclude that all is well. But then, someone picks up papers, a briefcase, or some other object from the floor, right where you were about to walk. You hadn’t seen it. Your vision is fine, so how could you have missed it? It makes you wonder how many other little things you missed in other places, too.

See More
Preventive Maintenance

Grid Coupling: How Does a Component Fail?

The next step that we talked about was, “How did the component fail…the grid coupling?” This is something that a lot of times, once we start doing this, for a grid coupling, if we set up a PM for this you can probably step straight to what kind of inspections would you do and you guys could tell me in three minutes and they’re probably pretty much right on. But I’m using something simple because I didn’t know who’s going to be in the class and what kind of technical skills you guys have. But using something simple and showing you the steps of how we break this down.  I think if we say how would you inspect a coupling that’s going on the run or doing what kind inspections do we need to do and shut down. I think you guys can tell me that. I’ll show you steps anyways so you can see the thinking process using something fairly simple.

See More
Preventive Maintenance

MEMS Accelerometer Performance Comes of Age

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.

See More
Preventive Maintenance

Vibration Analysis: 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.

See More

Join the discussion

Click here to join the Maintenance and Reliability Information Exchange, where readers and authors share articles, opinions, and more.

Get Weekly Maintenance Tips

delivered straight to your inbox