Page 17 - Simplified Wastewater Treatment Fundementals\Pumps and Pumping
P. 17
Pumps and their Applications
The second category of pumping are Positive Displacement Pumps.
Positive displacement pumps are powerful, capable of pulling and pushing liquids,
sludge and solids great distances under high stress.
Positive displacement pumps are designed with close tolerances.
The pump’s progressive cavities push liquid, or sludge in one direction only. Positive
Displacement Pumps typically include a downstream emergency pressure relief
valve designed to open at a specified pressure in the event a discharge valve is
mistakenly closed.
This device protects the pump and discharge piping.
Note - Closing a discharge valve on a positive displacement pump could result in
catastrophic damage to the pump, pipe and even YOU!
