Pumps & Systems, September 2008

Ensuring your sodium hypochlorite chemical feed system is properly set up and maintained is crucial to effective operation. Failure to address certain issues will decrease reliability, flexibility and performance. For optimal performance, follow these simple steps:

Pumps & Systems, September 2008

Last month, we used a hypothetical example to illustrate the onset and effects of water hammer. This month we will investigate its major causes and gain an even better perspective on the variables that contribute to its intensity.

Pumps & Systems, September 2008

A recent call to troubleshoot a horizontally-split multistage pump reminded me of my good old days working for an OEM. When an OEM de-stages a standard design, an important engineering step is properly sizing the center bushing. Unfortunately, when requested to de-stage a multistage pump, some repair shops do only that. They take one (or several, depending on the target flow/head/power conditions) of the stages off, replace it with a straight-through bushing and leave all the remaining internal components intact.

A note from Robert X. Perez:

Welcome to this installment of Compressor University!

Most high-speed centrifugal compressors rely on fluid film bearings-such as tilting pad journal (TPJ) bearings and equalized (Kingsbury style) thrust bearings-for rotor support and positioning. A compressor's rotor position must be maintained within a few thousandths of an inch to operate efficiently and reliably. A bearing failure will not only mean a compressor shutdown; it could also result in secondary or peripheral damage to costly internal parts. Early detection of a bearing failure may only result in an outage lasting a few days, but an undetected failure, causing major internal damage, can force an outage for weeks or months. 

Pumps & Systems, September 2008

Today, there are ever increasing economic and environmental needs to minimize industrial leakage and emissions. Continued developments in valve packing design and materials have greatly improved the abilities of compression packings to provide reliable sealing performance for years in a wide range of applications and valve types. Proper installation and maintenance are essential to achieve optimum performance from these packings. Since the majority of the current emissions come from valves, an understanding of the importance that proper valve packing gland loading has on meeting these needs is essential. 

Pumps & Systems, September 2008

Q. When operating centrifugal pumps on corrosive or erosive applications, how can the user determine when the casing wall is worn too thin for safe operation? What is the minimum safe operating wall thickness?

Pumps & Systems, September 2008

There are two largely accepted facts about mining: 1) A mine's landscape is dynamic, and 2) Within that landscape, water is a mine's worst enemy. Navigating a mine's landscape with pumps designed to move and/or remove water has long been the challenge of mine operators.

Pumps & Systems, September 2008

Mercator Mineral Ltd. officials needed to expand and streamline a freshwater supply system for an expansion of Mineral Park Mine, its wholly owned open-pit copper and molybdenum mine near Kingman, Ariz. For this water supply system, they needed an energy-efficient solution that integrated key controls within a network of multiple pump stations.

Pumps & Systems, September 2008

Valves used in flotation cells, dewatering service, cyclone separators and tailing applications tend to wear out quickly, so mining companies spend thousands of dollars replacing expensive valves and parts. One solution to this dilemma is elastomer-lined valves, including pinch valves and slurry knife gate valves.

Due to high specific gravity, viscosity and particle size of mining materials, centrifugal pumps are continuously challenged in mining applications. New pump technology was created to efficiently move mining materials with less downtime.