Priming the pump
Problem: Pumps with large-volume suction lines that run above the fluid level are often difficult to prime.
Problem: Pumps with large-volume suction lines that run above the fluid level are often difficult to prime. The problem results from the large amount of air that must run through the pump, plus the requirement to lift the fluid from the reservoir into the suction line. Simply filling the pump with fluid is not enough, and the suction line cannot be filled because it drains back into the reservoir. A foot valve is often undesirable or unavailable. Is there another way around this problem?
Solution: Install a port (1/4-in. pipe) at the highest point on the suction line, and attach a small venturi with plant air flowing through it. Open the valve in the pipe. Air flowing through the venturi creates a vacuum at the highest point and draws the fluid into the line until all air is evacuated. At this point, fluid begins to flow out the hose attached to the venturi exhaust, along with plant air. Close the valve in the pipe. The suction line and pump are now full of fluid. Compressed air is disconnected from the venturi, and the pump started.
Contributor: John R. Giegel, PE, Plant Mechanical Engineer, Werner Co., Greenville, PA; 724-588-2000 x 2439
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Annual Salary Survey
Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.
There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.
But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.
Read more: 2015 Salary Survey