Pumps & Systems, March 2008

The difference between the ported disc butterfly valve from Kubota Corporation (Osaka, Japan) and a regular butterfly valve is on the disc. The disc has a fin-shaped disc tail attached to the edge of a butterfly disc, on which an oblong hole-the flow mouth-is made. The hole serves as a bypass valve. An excessively big disc tail increases the valve's pressure loss, so the unit is designed to achieve the least possible pressure loss.

Pumps & Systems, March 2008

Whether you are a multinational OEM or a mom-and-pop shop, pump systems are expensive and need to be protected. The protection system for the pump is a vital piece of the system and often can make or break a company financially. If a refinery on the Gulf Coast loses a pump or two, the company could lose millions. If a pump on the heating system of a store in the Maine North Woods fails, the pipes may freeze and the building could suffer serious damage.

Pump operators and pump manufacturers must understand the best practices for protection and return on investment. This article examines some of these protection systems and describes the best way to install them.

Pumps & Systems, November 2007

Our repair shop came upon a customer that purposely buys oversized pumps and immediately operates them at nearly 80 percent closed valve. Each year, after the hot days of summer simmer down, they evaluate the pumps' performance by measuring flow. If the flow dropped by more than ~10 percent, they slightly open the valve (say 70 percent closed) to compensate and run the pump at this new valve position the next season.

Pumps & Systems, August 2007

Editor's Note: Due to the high number of responses from our readers for more information regarding valve applications in "Surge Control in Pumping Stations" (Pumps & Systems, March 2007), this article serves as a follow-up to that discussion.

Buying complex products and services can be just that . . . complex. Engineers like David Griffiths at New York Air Brake need to design and assemble solutions that perform under great pressure, with no room for error or downtime. Griffiths' job is to find simple, elegant solutions to complex problems in the well-established rail industry. He expects the same from his suppliers.