Water shortages, failing infrastructure, broke governments, a crumbling municipal bond market and the need for high subsidies. While the global pump community tools up to participate in the business of water, the question remains: From where will the funding come?
In the late 90s, I used Excel to develop a simple graphical system that showed the variable speed performance of a pump based upon its published 60-hz H/Q curve. I have modified it to model several different pumping applications, and four different versions are on my website today.
Part One of this series addressed potential reliability improvements from using nonmetallic wear rings with reduced clearance. Part Two evaluated the efficiency gains from reduced clearance. In this final look at pump wear rings, the safety impact of nonmetallic rings with reduced clearances is examined.
Some may question if this is an appropriate topic for a pump magazine. While I do admit that I am a staunch conservative, this column is not about the political left. Instead, it addresses a very different left-the left side of a centrifugal pump's performance curve.
When the motor amps are kicking a unit offline, the first question is whether the motor or the pump is the problem.
Multiple pumps operating in complex systems can be synchronized and controlled by a computer. In this column, I will discuss several simplified cases, to give an idea of how pump system interactions are handled and what is involved. This column will also discuss how friction, static, and combination system hydraulics affect the system's results.
 |
