September 2012

				

 			
		 

		 

	
		
 
		


			
			
		
 
            			
					
			
	







	



		


		
				
				
				  

    

  

            
    

      

        
  
  
      

      

  

    





	
	
Characteristics of Centrifugal Pumps
		
Characteristics of Centrifugal Pumps

	
		
Head, performance curve and affinity laws all contribute to the efficiency of centrifugal pumps.

	
           
        	













  



  

    





	
	
Open-Delta Systems Affect Variable Frequency Drives
		
Open-Delta Systems Affect Variable Frequency Drives

	
		
To avoid premature drive failure, proper precautions must be taken when installing VFDs on open-delta supplies.

	
           
        	













  



  

    





	
	
Plant Upgrades Improve Efficiency at Midwest Refinery
		
Plant Upgrades Improve Efficiency at Midwest Refinery

	
		
Equipment and technology improvements can be sound investments.

	
           
        	













  



  

    





	
	
Stainless Steel Motors
		
Stainless Steel Motors

	
		
In the food industry, stainless steel performs more productively and efficiently.

	
           
        	













  














  

    





	
	
Top-of-Motor Vibration
		
Top-of-Motor Vibration

	
		
A simple mathematical model can be used to estimate vibration at the top of the motor in a vertical pump-motor structure.

	
           
        	













  



  

    





	
	
The Bernoulli Principle
		
The Bernoulli Principle

	
		

	Read Part OneRead History of Pumps seriesThe Bernoulli Principle explains the flow of fluids and was one of the earliest examples of conservation of energy. It states that during steady flow, the...	

	
           
        	













  



  

    





	
	
Dry Gas Seal Conditioning Systems
		
Dry Gas Seal Conditioning Systems

	
		
Ensure proper gas flow and determine gas quality required for reliable operation.

	
           
        	













  



  

    





	
			
Grinder Pumps in a Low-Pressure Sewer System

	
		
A Tennessee community review shows increasingly positive operation and maintenance statistics.

	
           
        	













  












  

    





	
	
Grinder/Cutter/Shredder Pump Resolves Sewage Clogs
		
Grinder/Cutter/Shredder Pump Resolves Sewage Clogs

	
		
New cleaning and personal disposable wipes can cause major pumping problems.

	
           
        	













  



  

    





	
			
Maintenance for Dependable Pumping

	
		

	There is a saying that “You don’t know what you’ve got until it’s gone.” This concept can be all too familiar for anyone who has ever neglected a pump. A dependable pump is not truly...	

	
           
        	













  



  

    





	
			
How Important Is Accounting  for Velocity Head and Gauge Elevation? (Part 2 of 2)

	
		

	Part 1 (Pumps & Systems, August 2012) discussed an example in which neglecting corrections for velocity head and gauge elevation did not introduce significant errors in the calculations. Part 2...	

	
           
        	













  



  

    





	
	
New Progressive Cavity Pump Technology
		
New Progressive Cavity Pump Technology

	
		

	Progressive cavity (PC) pumps are commonly referred to in industry as mono-pumps, screw pumps, eccentric screw pumps or worm pumps. All are positive displacement pumps. The inventor of the progressive...