Tuesday, June 19, 2018

Industrial Vibration Monitoring

Vibration Monitoring
Vibration Monitoring
All you have to do is drive in a car to understand that failing mechanical systems create symptoms that can be detected by our sense of feel. Vibrations in the steering wheel may indicate bad steering linkage. Transmission wear may manifest as loud or hard gear shifting. Exhaust systems that have come loose may be felt as in the floorboards as vibrations. All of these have one thing in common - degradation of a mechanical device beyond design specifications to the point of creating abnormal levels of vibration.

What is vibration?

Vibration is defined as “an oscillation of the parts of a fluid or an elastic solid whose equilibrium has been disturbed.”

Asset Monitoring on Large Equipment
Asset Monitoring for Large Equipment
Most important to understand is that vibration is motion, and that motion cycles around a position of equilibrium. Simply touch a running machine and you know if it's running or not, because the machine's motor creates a vibration which is transmitted to the other areas of the machine. In some machines, many parts can be rotating simultaneously, with each contributing it's own unique pattern of vibration. Human touch merely senses the sum of all these vibrations because touch is not sensitive to distinguish the individual differences. Vibration detection instrumentation and signature analysis software can sort out the various vibration components using sensors to quantify the magnitude of vibration, and more accurately determine how rough or smooth the machine is running. Vibration amplitude and the magnitude of vibration is expressed as:

Vibration Sensor
Sensor
Acceleration – The rate of change of velocity. Recognizing that vibrational forces are cyclic, both the magnitude of displacement and velocity change from a neutral or minimum value to some maximum. Acceleration is a value representing the maximum rate that velocity (speed of the displacement) is increasing.

Velocity – The speed at which a machine or machine component is moving as it undergoes oscillating motion.

Displacement – Also known as “peak-to-peak displacement”, this is the total distance traveled by the vibrating part from one extreme limit of travel to the other extreme limit of travel.

A variety of sensors are available that will sense vibrational displacement, velocity or acceleration, and provide a proportionate, measurable output signal. Applying these sensors depend largely on the machine condition with the help of limited guidelines published to determine the relative running condition of a machine.

Sensor Installed on Motor
Sensor Installed on Motor
Vibration signature analysis can be used in defining the exact machine location of the vibration and what component of the machine is in need of repair or replacement. When the vibration magnitude exceeds a predetermined value, sensors and software can narrow down the individual vibration signals and separate them via vibration magnitude and frequency. Combined with a little machine design understanding, a person schooled in vibration signature analysis can interpret this information to define the machine problem down to a component level. However, there are no guidelines to determine the absolute  limits of failure or indefinite life for machines. It is simply not possible to establish absolute vibration limits. Predictive maintenance programs are intended to establish severity criteria or limits above which action will be taken and monitor the overall condition of machines.

Vibration monitoring and analysis is used to uncover and predict a wide variety of problems related to rotating equipment, such as:
Predictive analysis for wind turbines
Predictive analysis for wind turbines.
  • Sleeve-bearing problems
  • Gear problems
  • Unbalance
  • Belt drive problems
  • Eccentric rotors
  • Flow-induced vibration problems
  • Rolling element bearing problems
  • Mechanical looseness/weakness
  • Misalignment
  • Resonance problems
  • Electrical problems
  • Rotor rub

Determining or predicting the presence of these problems is difficult, but asset monitoring technology is advancing quickly. As progress is made, modern manufacturing and production facilities can look forward to tremendous safety advancements and large cost savings through reliable and accurate predictive failure analysis.

Contact Arjay Automation to discuss your vibration and asset monitoring requirement. You can find them at https://arjaynet.com.

Wednesday, June 6, 2018

A Pressure Transmitter Design with Overpressure Protection

Overpressure Protection
Overpressure Protection Design
Overpressure can cause a pressure transmitter to fail or impair its performance. This effect happens when excessive differential pressure is applied to the device which is greater than its measuring range. Overpressure can occur from improper manifold sequencing, startup and shutdown conditions, or a sudden process upset. Yokogawa's unique capsule design equalizes overpressure within the capsule before it can reach the measurement sensor. Therefore Yokogawa's pressure transmitters prevent failure and minimize any performance impact from overpressure events. Overpressure protection provides
  • Increased reliability from reduced failures
  • Improved long-term stability in real-world conditions
  • Reduced maintenance costs through fewer unscheduled calibrations
The video below demonstrates how this is done.

For more information, contact Arjay Automation by visiting https://arjaynet.com or calling (800) 761-1749.