1. Regenerative Converter Units in AC Drive Systems
(Matching tags: Controls,Instrumentation/Controls,November 2009 Issue)

Regeneration occurs in an AC variable frequency drive system when the load overhauls the motor. This can occur when trying to decelerate the load, or when some external force causes the motor to overhaul ...

2. Design Challenges for Pump Applications
(Matching tags: Seals,sealing technology,November 2009 Issue)

From an overlooked stress concentration in the hull plating on a Liberty ship to the aero-elastic flutter of the original Tacoma Narrows Bridge, miscalculating small details has led to public disasters. ...

3. Pump Rebuilding and Balancing (Part One)
(Matching tags: Centrifugal Pumps,pump maintenance,November 2009 Issue)

Pumps and pump systems are unique, engineered products that require specialized knowledge in all phases of repair, rebuilding and balancing. When pumps fail, costs add up quickly for repairs, replacement ...

4. Why Replace It When You Can Wrap It?
(Matching tags: November 2009 Issue,Piping)

With production time and cash flow at an all time premium, more companies are looking for time and cost saving alternatives to replacing slightly damaged assets. In a refinery, for example, it is common ...

5. Wireless Technology Reduces Maintenance Costs
(Matching tags: November 2009 Issue,Instrumentation/Controls)

Wireless technology is enabling INEOS Köln GmbH (Cologne, Germany) to detect blocked filters in polyethylene pellet transportation tubes that can lead to production downtime at its plant in Cologne.

6. Binder Transfer in Paint and Coatings
(Matching tags: November 2009 Issue,Rotary Pumps,Chemical)

The Challenge A paint and coatings plant that produces both cationic paste with pigments and cationic binders without pigments for truck shipment to automotive OEMs was experiencing difficulties when ...

7. What are the basics of gas lubricated seals? (Part One)
(Matching tags: Mechanical Seals,Seals,FSA Sealing Sense,November 2009 Issue)

The use of gas lubricated mechanical seals in pumps has increased for a variety of reasons. This two part article will address the principles of gas seals, some basic application questions, what to expect ...

8. Hydraulic Institute Pump FAQs November 2009
(Matching tags: November 2009 Issue,Hydraulic Institute Pump FAQs,Reciprocating Pumps)

Q. What is an acceptable amount of residual unbalance in an impeller after it has been balanced? A. High levels of residual unbalance in rotating parts can generate high unbalance forces, resulting in ...

9. Using Synthetic Diamond to Improve Machine Performance
(Matching tags: November 2009 Issue,Machinery Health,Bearings)

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 ...

10. Lip Seal Leaks in Gear Reducers
(Matching tags: November 2009 Issue,Maintenance Minders,Seals)

Seals are a commodity to some users, but seals are the most critical element of the system for other users. If a $2 seal fails and causes $500,000 in repairs and/or warranty costs, it emphasizes how important ...

11. Solution to Pump Challenge #4
(Matching tags: November 2009 Issue,Energy Efficiency,Pumping Prescriptions,Centrifugal Pumps)

In Pump Challenge #4, many of you discovered while using the Energy Consumption Evaluator, that the standard listing only goes to 8x6-17 pump size with motor power maxed at 250 hp, which is below the larger ...

12. Pump Challenge #5: Correctly Sizing Pipe
(Matching tags: November 2009 Issue,Pumping Prescriptions,Piping)

Click here for solution to Pump Challenge #4 Consider a typical ANSI-dimensioned 1x1.5-6 pump, as discussed in the P&S August article. The performance curve showed the BEP flow at around 100 gpm. ...

13. Corrosion: A Natural Process
(Matching tags: Piping,Joe Evans,November 2009 Issue)

About 900 years before Newton formulated his universal gravitational theory, the Greek philosopher Aristotle espoused something different. He believed that all things had a natural place in the universe, ...

14. Suction Specific Speed (Part Three): Using Suction Specific Speed to Establish Adequate NPSHA
(Matching tags: November 2009 Issue,NPSH,Centrifugal Pumps)

Tenth in a Series A number of technical papers (1, 4, 7, 8) have shown that the maximum damage rate to centrifugal pumps, at least in water services, typically occurs when the NPSHA is in the range ...