What is a Sump Pump?
A Sump Pump is a pump used for drainage that removes accumulated water from a sump pit or other location. A sump pit, commonly found in the home basement, is simply a hole dug in the ground to collect water. The water may enter via perimeter drains funneling into the pit, or may arrive from natural ground water in the earth.
How are sump pumps typically used?
Sump Pumps are installed particularly where basement flooding is seen as a problem, but are also used to ameliorate dampness by lowering the water table under the foundation. Sump pumps pipe water away from the house to any place where it no longer presents a hazard, such as a municipal storm drain or dry well. Older properties may have their sump pumps connected to the sanitary sewer, but this is frowned upon now (and may be against the plumbing code) because it can overwhelm the municipal sewage treatment system. Though in some cases, a sump pump is used when a lower floor is below the sewer lines, to pump greywater or blackwater waste from that floor to the lines.
What types of sump pumps are available?
There are two available categories of sump pumps, Automatic and Manual. An automatic sump pump has a switch attached that activates the pump when the water reaches a certain height and turns the pump off when the sump pump has drained the water. A manual sump pump must be turned on and off manually. Sump pumps may also have battery backups, control panels, and automatic switches amongst other accessories installed to ensure continuous and proper operation.
Reading a Pump Curve
A Pump curve tells you the flow performance (measured in gallons per minute or liters per minute) of a pump relative to the head pressure. To read a pump curve, you must first examine the units of measurement used along each of the displayed axes. The pictured pump curve displays head pressure in Feet (along the left-side y-axis) and in Meters (along the right-side y-axis). Increased head pressure is indicated as you travel up the y-axis. The flow performance is indicated in gallons per minute (along the lower x-axis) and liters per minute (along the upper x-axis). This is an indication of the output flow of a pump.
The pump curve is read by first determining the head pressure of the application in which the pump will be used. Once you�ve determined your head pressure, simply follow the head value you have selected from the y-axis horizontally to where it intersects with the pump curve line. From that point, move vertically to the flow measurement on the x-axis.