The plunger type positive displacement pump
was first introduced to the municipal wastewater treatment
industry by the Ralph B. Carter Company in the early 1930's.
From that time to now, the plunger pump has been a mainstay
of wastewater treatment plant design. The significant reason
for this durability of application has been the success of
this pump design in handling both the difficult to pump sludge
streams with in the treatment process, and in a pump design
which allows for the often erratic service and maintenance
procedures practiced at many municipal plants. Although no
piece of equipment can function without service or significantly
beyond design parameters, the plunger pump's simple and basically
rugged design will, in most cases, "forgive" poor
maintenance and periodic excess pressure and load conditions
without failure. The dividend of proper maintenance and application
has been extremely long service life, in some cases, as long
as 45 years of continuous operation.
What is a Plunger Pump?
A plunger pump utilizes ball type check valves to direct the
reciprocating action of a plunger into a useable pumping force.
The check valves are mounted to the pumping chamber so that
one valve, suction, will allow fluid only to pass into the
pump, and the other pump, discharge, will only allow fluid
to flow out of the pump. As the plunger moves upward from
its lowest point of travel, a vacuum is developed which will
seat the discharge ball valve and raise the suction ball valve.
Fluid will then flow into the pump chamber. Once the plunger
has reached its highest point of travel, the hydraulic circle
is complete. As the plunger now moves from the high position
, a positive pressure is developed, with this pressure seating
the suction ball valve and raising the discharge ball valve
allowing the fluid to flow out of the pump.
