"Can we put this pump outdoors without an enclosure?"
February 3, 2011
From time to time, we're asked if a particular pump can be put into service outdoors without an enclosure. Obviously, the answer depends upon the circumstances -- but the answer is usually "Well, it could...but you don't want it to." The low temperature in Chadron, Nebraska, yesterday was 27 degrees below zero
. That's the air temperature alone. Add in the tiniest breeze, and that would have felt like -40
The thing about operating pumps in these conditions is not so much that the machinery itself can't handle it -- but that the water being pumped at that temperature is so likely to freeze. (There are YouTube videos
to this effect, showing how even boiling water can freeze nearly instantly at well-below-zero temperatures.) Thus the problem, more than anything else, is the water itself. Inside the suction and discharge piping, water will tend to freeze along the walls of the pipe first, changing the effective inside diameter of the pipe and quite possibly pushing the pump's performance right off the operating curve by dramatically changing the total dynamic head (TDH). The water can also freeze inside the pump and cause the pump casing or piping to crack (since water expands when it turns to ice).
All of this is logical enough from a physics view, but the human angle is just as important: Should the pump need maintenance of some sort, who wants to work in -27° weather -- or even can, for more than a few minutes? Pump station enclosures
are highly cost-effective and can significantly improve the working environment while protecting valuable equipment. Since we ourselves sometimes have to work on pumps for maintenance and installation, we're strong believers in enclosing every pump.
last revised February 2011