Explore some of the issues associated with vertical pump bearings in general, and nonmetallic bearings specifically. Nonmetallic bearings may not be the best answer in every case but have been an excellent choice for many applications worldwide. In general, these product-lubricated bearings preclude additional contaminants (oils, greases) infiltrating the pumped fluid.
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Babbitt bearings, frequently found in large steam turbines and generators in major power plants, can provide years of service if properly maintained. By using state-of-the-art technology and repair practices, aftermarket suppliers who specialize in Babbitt bearings can repair equipment and increase the life of Babbitt bearings.
The benefits of predictive maintenance are becoming readily accepted throughout industry in Europe as well as North America. Guy Mertens, who is responsible for predictive maintenance at the Belgian Refinery Corporation (BRC), added an extra dimension to his predictive maintenance program by using it to identify common machine faults for the maintenance staff to watch for.
For more than 25 years Shock Pulse has proven to be a valuable method for evaluating bearing condition. Shock Pulse is easy to use and understand. With the addition of enveloping to the Shock Pulse signal, a more exact diagnosis is available, allowing end users to identify the damaged component within the bearing.
Given time, every component of the rotating machinery will eventually fail, even when operating in a perfect environment. For instance, rotation of the shaft subjects it to alternating load, changing from tension to compression with each shaft revolution.
When a component of a large circulating water pump fails in a power plant, the power plant must often spend hundreds of thousands of dollars to remove the pump from service, replace the failed component, rebuild the pump and return it to service. In addition, circulating water pumps can require work on a massive scale-they can measure 30 ft or more in length and pump an average of 165,000 gpm. Rotating shafts for these pumps can measure 8 to 10 in. in diameter.
Progressive maintenance practices are vital to maximize pump life, minimize downtime and avoid costly repairs and lost production. It is good practice to plan the detailed groundwork of maintenance programs, along with contingencies for various maintenance events to minimize downtime.
Pump manufacturers in a variety of industries are increasingly asked to deliver more with less; they need to handle increased loads with improved system efficiency but reduce envelope, environmental impact and total system cost.
Knowing the basics of pump repair can simplify preventive maintenance.
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Pump manufacturers in a variety of industries are increasingly asked to deliver more with less; they need to handle increased loads with improved system efficiency but reduce envelope, environmental impact and total system cost.
An unexpected bearing failure needs to be understood and seen as an opportunity for improvements.
It has been 54 years since Tracy Hall invented the first manmade diamond at the General Electric (GE) laboratories in Schenectady, New York. Since then, synthetic polycrystalline diamond (PCD) has found wide use as an abrasive and as a cutting element, with an annual market of $4 billion (3 billion carats in 2005).
Lubricants for rotating machinery primarily serve to separate rolling and sliding contact surfaces, protect highly finished bearing surfaces from corrosion, protect against contaminants (in the case of grease) and serve as a heat-transfer medium (in the case of oil). An effective lubricant management program-grounded in proper lubricant monitoring and analysis practices-can help reinforce these functions and, in the process, deliver vital information about the machinery's condition and health.
For more than 25 years Shock Pulse has proven to be a valuable method for evaluating bearing condition. Shock Pulse is easy to use and understand. With the addition of enveloping to the Shock Pulse signal, a more exact diagnosis is available, allowing end users to identify the damaged component within the bearing.
Bearings perform vital roles in enabling optimized operation and service life of pumps used throughout industry. In centrifugal pump applications, for example, crucial functions abound.
Progressive maintenance practices are vital to maximize pump life, minimize downtime and avoid costly repairs and lost production. It is good practice to plan the detailed groundwork of maintenance programs, along with contingencies for various maintenance events to minimize downtime.
The pump is a 300-hp integrally geared propylene product pump in a Gulf Coast olefins unit that operates at 25,000-rpm and produces 6000-ft of head (see Figures 1 and 2). The suction and discharge pressures of the pump are 250-psig and 1500-psig, respectively.
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In this multi-part series, we will investigate several aspects of centrifugal pump efficiency.
First of Five Parts
Since the original publication of this draft standard in the January 2008 issue of Pumps & Systems, I have received feedback, encouragement, numerous questions and criticism. The draft listed three basic levels of repair.
The McGraw-Hill scientific dictionary [5] states that a volute is "a spiral casing for a centrifugal pump... designed so that speed will be converted to pressure."
