Vibration Monitoring of Pumps
Pumps are some of the most popular mechanical devices and an integral part of the plant. They are widely used in various industries to transfer liquids or gases, increase pressure, or circulate fluids within systems. They play a crucial role in numerous processes, including oil and gas production, chemical processing, water supply, water and wastewater treatment, cooling systems, and more.
Pumps move gasses or liquids from one area to another by accelerating the liquid using centrifugal forces in Centrifugal Pumps, or by grabbing a certain amount of liquid and physically pushing it towards where it needs to go, such as in Positive Displacement Pumps. Positive Displacement pumps are further categorized into Reciprocating and Rotary Pumps.
Maintaining pumps helps them last longer, and it also makes it possible to avoid process slowdowns that ultimately affect productivity. When you prioritize vibration monitoring for pumps, you can expect to see a notable difference in your operations.
Pump maintenance comes down to identifying and interpreting the forces that impact the pumps. Equipment reliability depends on how the different parts of the pump work together to operate successfully. If the pump experiences issues such as worn bearings, shaft misalignment, pump cavitation or other defects, it will have an impact on the vibration levels, and on the normal operation of the pump. Vibration monitoring sets a baseline for operators and technicians and helps them understand when a problem begins so that it can be addressed as early as possible. Instead of reacting to a mishap, they can proactively control the situation before it has the chance to develop further.
Please see below for a variety of vibration monitoring solutions for pumps from Metrix so that you can find the right one for your needs.
Centrifugal Pump Monitoring Solutions
440 Vibration Switch with External Sensor
Provides local contacts as well as 4-20mA output for interface with PLC. Sensor is located on pump while 440 switch is located in a more electronic friendly environment.
SA6200A Accelerometer and 5535 Accelerometer Signal Conditioner
Provides 4-20mA output for interface with a PLC / DCS. Dynamic signal is available from front panel for vibration analysis purposes. Provides options for custom filters, local display/indication, or galvanic isolation.
ST5484E Velocity Transmitter and ST5491E Indicating Transmitter
The ST5484E provides for the simplest installation available. Since it’s a loop-powered device, only two wires are needed for full operation. The ST5484E is connected directly to a PLC / DCS. Optional filtering and dynamic outputs are available. The ST5491E has a local indicator.
Monitoring Large Vertical Pumps
Large pump applications, such as the one shown above, require a more thorough monitoring scheme than smaller applications.
Metrix provides vibration sensors for all bearings and a Datawatch monitor. The Datawatch monitors all vibration and temperature readings and compares them to pre-programmed setpoints in order to change the state of alarm and danger relay outputs.
Monitoring Pumps with Journal Bearings
Journal bearings use a layer of oil to isolate the shaft from the bearing. Therefore, the shaft is actually floating on a cushion of oil and has no contact with any other metal. Because of the oil layer, a vibration signal produced by the shaft does not have a path to travel to the machine casing. That means that a seismic sensor placed on the case of the pump cannot properly sense what is going on with the shaft.
This makes it necessary to use proximity sensors to detect shaft faults. A proximity probe mounts through the case of the machine and senses the position of the shaft relative to the probe tip. The pump casing holds the probe steady so that any movement in the shaft will cause the proximity probe / transmitter to give an indication. This type of measurement is termed “relative” because the shaft movement is being measured in relation to the machine casing.