What Is L3/D4 and Why Is It Good for the Seals If It Is Low?   Pump Source April 2003
What is L3/D4 (L cubed over D to the fourth)? It is a measure of pump rotor stiffness, its ability to resist radial load and to minimize deflection. It comes from the basic cantilevered beam deflection formula, which you can find in any book on mechanics: y = F x L3 / (3 x E x I), where F is radial load, L is cantilevered length, E modulus is the elasticity of the material and I is moment of inertia.

The O-Zone: Today's Lesson: Ozone Installation   Water Quality Products February 2003   Roger Nathanson
The installation of ozone equipment on well applications utilizes the same principles and techniques as chlorinators, air injection and softener systems. There are only minor variations in sequence, parts and details.
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Prefabricated Pumping Systems   Water Engineering & Management February 2003   Tom Levey and Stephen Jeffus, P.E.
Some engineering firms still harbor the misconception that prefabricated systems are too small to handle the enormous volumes of water that municipalities and private water companies transport. Though once limited to certain-size projects, technological innovations and manufacturing breakthroughs have dramatically expanded the application of prefabricated pump systems over the past several years.
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Open Trench Failures Continue to Rise   Water Engineering & Management March 2002   Del Williams
Despite the fact that hundreds of people are killed and severely injured in open-trenching accidents throughout the United States every year, most municipalities continue to award construction contracts to companies utilizing open-trench methods, when safer trenchless technology is available to them.
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Infrastructure Relocation for a Growing Urban Community: Juggling Schedules and Methods   Water Engineering & Management March 2002
In the last decade, municipal leaders of medium-sized cities across the United States have rediscovered downtown urban centers. Economic development initiatives and long-term growth once again focus on these areas. As plans for revitalizing downtown neighborhoods begin to take shape, local governments are finding that existing infrastructures are inadequate to support the utility needs of incoming commercial and residential tenants. As a result, the need for infrastructure rehabilitation and utility service expansion is in high demand.
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High-Quality Water Deserves a High-Quality Connector: The Importance of RO Installation   Water Quality Products May 2000   David F. Walling
Thirteen years ago many people believed technology would take care of all the hurdles involved in the treatment process called reverse osmosis (RO). However, technology cannot correct poor installations; that is up to the person who does the job.