August 12, 2014
Recently I visited a customer’s facility to provide onsite training for the VibXpert vibration data analyzer they had recently purchased. Before we could get started collecting data, we needed to build the equipment hierarchy and measurement templates required. Once the database was created, we loaded routes into the VibXpert and proceeded to collect vibration data.
The first room we entered had two large belt driven overhung fans. At first glance it was obvious that one of the fans was running extremely rough. We collected vibration data on both fans and paused to review the results. We noticed that the 1× amplitude on the rough fan was over 1.0 inches per second peek. The local CM technician immediately commented that the fan should be balanced and his observation was correct when simply looking at the vibration data.
The room was full of clues which explained the cause of the fan unbalance. This facility processed and manufactured wood products. Large amounts of wood dust are produced and these fans were designed to ventilate a high dust area. Everything in the room was covered with wood particles and dust. The only question was how much had accumulated on the inside of these fans.
I asked if the fan could be stopped for a short period and the inspection door opened. My request was honored and the fan was shut down and locked out. Our examination revealed the fan blades had amassed substantial amounts of wood particles. The fan blades were cleaned and resulting in a pile of wood chips weighing about 5 lbs. The fan was placed back into operation and allowed to run for several minutes. Vibration data was recollected on the fan and the 1× amplitude had reduced to 0.1 inches per second.
Fans require corrective action to eliminate unbalance conditions from time to time. However, the cause of unbalance may simply be buildup of foreign matter on the blades. This fan was being allowed to beat itself to death due to product buildup. This facility learned a few lessons from the experience. First, inspections utilizing the human senses (touch, hearing, etc) could have been used to determine that this fan was in need of attention. Second, periodic vibration monitoring would have identified a need for maintenance on this fan. Third, if a fan is properly balanced, simply cleaning foreign matter buildup may reduce the vibration, prevent equipment damage and maintain the reliability of the equipment. Make sure that you utilize these three steps during your daily maintenance efforts on equipment.
August 7, 2014
“Thermal growth” often refers to the change in machinery positions as a machine runs from startup to operating conditions (or vice versa). Machinery positional change can also be caused by dynamic forces, pipe stress and other factors. Compensating for thermal growth is necessary because the machine will be misaligned during operating conditions if it is not. —Daus Studenberg, Applications Engineer – LUDECA, Inc.
Thermal Growth and Machinery Movement Crash Course Video
Machinery movement and thermal growth are two of the main issues that affect operation and life of machinery. Watch our crash course video and see how continuous monitoring of positional change can eliminate checks and calculations and provide an exact solution.
August 6, 2014
We will have all our shaft alignment, pulley alignment and vibration analysis and balancing maintenance-related products on display at the following trade shows:
TURBOMACHINERY AND PUMP SYMPOSIA
September 23 – 25
Download FREE Pass
NORTHERN CALIFORNIA FACILITIES EXPO
September 24 – 25
Santa Clara, CA
Attend our session: Field Balancing – Tips and Tricks by Greg Lee, Sept 24 – 9:35 am
Download FREE Pass
Sept. 29 – Oct 1
New Orleans, LA
August 5, 2014
Advanced vibration analyzers like the VibXpert have powerful analytical features that often go underutilized. One such feature is the ability to acquire continuous (live) vibration measurements. This can be utilized to check for measurement signal stability and quality. However, it can also be used for additional analytical troubleshooting as well. Continuous (live) vibration data can be used to determine if electrical energy (faults, etc.) is present in electrical motors. Set your vibration analyzer to continuous monitoring. Identify and watch the peaks in question. Turn the motor off while watching the peak(s) in the measured data. Peak(s) that disappear immediately when motor power is turned off are related to electrical energy. Remaining vibration data is associated with rotating components within the equipment.
Continuous data collection can be activated in the VibXpert analyzer by selecting the Multi-Mode icon and then the Data Collection icon that will be used. Press the Menu key, select the display setup option and toggle continuous measurement to “Yes” (it is set to “No” by default). Alternatively, you can activate the live mode by keeping the “Enter” key pressed when the measurement starts. The actual data collection begins when you release the “Enter” key.
July 31, 2014
Guest post by Brad Loucks, Mechanical Engineer at Pioneer Engineering
In a condition monitoring vibration program, determining the appropriate intervals of data collection is just as important as the data that is being analyzed. Properly scheduled data collection intervals of equipment provides data analyst with a better picture of how equipment is performing over a period of time. Having a history of data is important for in an effective condition monitoring vibration program and this is done by establishing correct data collection intervals.
Data collection intervals should be established and executed with purpose, not done randomly. To establish intervals, it is important to know and understand how equipment works. Determining the appropriate time interval between collections is done by identifying how often the equipment runs, how fast it runs, and the application. The calculations are based on the estimated life cycle of the bearings but also the estimated amount of time it takes to go from a defect to complete failure.
Collection intervals should be a routine function. Many times data collection falls behind because the collection person is too busy to collect the data. One of the most common issues that I have come across is that plants will begin to collect data and then the person collecting the data gets pulled to do other work and the data collection gets missed and becomes more random. This is a slippery slope in that it almost always leads to the data no longer being collected. Then when an emergency comes up such as a bad sounding machine, the analysis has not been collecting a history on the equipment but they have also been out of the analysis for so long that they have a difficult time remembering how to analyze. The history and interval is just as important for a proper analysis as it helps to give the analyst a more accurate analysis by allowing them to see the progression timeline.
Bearings often do not fail in a predictable time span. If this were the case, vibration analysis could be overlooked and time-based maintenance could be used. A bearing can go from a known defect to catastrophic failure over the course of a few years or it can happen within minutes. The collection intervals are calculated so that not only can data be collected and the severe defects be identified, but also to identify when a defect has formed and allow for a history to be built in order to watch the progression of the defect. This can aid in determining whether immediate action should be taken or if the defect is at an early enough stage where proper planning and measures can be taken to avoid an immediate shut down and loss of production.
If the equipment is deemed valuable enough or if unplanned downtime is just out of the question, then calculated collection intervals are a necessity of a proper condition monitoring vibration program. Through proper maintenance, a condition monitoring vibration program can save a plant both time and money in reducing or eliminating unplanned downtime, as well as significantly reduce the possibility of injury or death of plant staff due to catastrophic equipment failure.
Download our Calculations of Bearing Defect Frequencies
July 29, 2014
Engineering advancements have resulted in many different types and grades of lubricants being available for equipment maintenance. Unfortunately, the risk of improper selection and mixing of lubricants has increased as well. Mixing different types of lubricants (grease and oil, etc.) within a machine is one of the most common equipment reliability problems. Doing so can result in unanticipated chemical reactions and equipment failures.
Proper labeling is a method to help ensure that the correct type of grease or lubricant is being injected into your equipment. Color coded labels with proper lubricant identification markings should be placed on the Zerk fitting or near any lubrication entry point on a machine. Grease guns and lubricant containers should have the same color identification and markings as well. This simple process can assist in eliminating lubricant contamination and thereby prevent one of the most common reliability problems today.