Stand-Alone Pressure Motive Pumps (PMPs)
Pressure Motive Pumps (PMPs) are pressure driven pumps which return
condensate back to the boiler room; normally using steam pressure as the motive
force. PMPs can be supplied as individual pump units – which include a pump
tank, the internal pump mechanism, and a set of inlet and outlet check valves –
or as a packaged system which also includes the vented receiver mounted on a
common base.
A separate vented receiver is required for the Pressure Motive Pump (PMPs)
to operate. The vented receiver collects and temporarily stores the condensate
during the PMPs’ discharge cycle when the pump tank is pressured with steam.
(See purpose of vented receiver)
PMPC
Ductile Iron
Significantly more corrosionresistant
to condensate when
compared to carbon steel.
PMPNT
Ductile Iron or Stainless Steel
(Low-Profile)
For lower capacity applications.
PMPF
Fabricated Carbon Steel
Carbon Steel may be required
by code in Chemical and
Petro-Chemical industries
(required in certain industries).
PMPSS
304L Stainless Steel
(Corrosion Resistant)
Can serve as a substitute for
fabricated carbon steel tanks
for extended life or when
Stainless Steel is required.
PMPBP
Carbon Steel
(High-Capacity)
For applications requiring
large transfer rates of
condensate or other liquids.
What is the purpose of a Vented Receiver
The condensate return piping is connected to the inlet of the vented receiver to initially collect the condensate prior to the pump. The receiver tank
will temporarily store the condensate during the PMPs’ discharge cycle when the pump tank is pressurized with steam. Condensate flows by gravity
from the vented receiver to the pump and is then returned back to the boiler room. The receiver and vent must be adequately sized to allow for
proper flash steam separation without building up pressure inside the receiver. Higher condensate pressures and temperatures, or higher
condensate loads require larger receiver and vent sizes. By connecting the condensate return line to a vented receiver, the pressure in the return line
will be effectively equalized to atmospheric pressure, allowing condensate to freely drain from all condensate sources. This is an extremely important
and often overlooked aspect of any properly operating steam and condensate return system.
PMPs with a Vented Receiver (Complete Package Systems)
As an option to a Stand-Alone PMP pump, Watson McDaniel offers Complete Packaged Skid Systems (Simplex, Duplex, & Triplex) which include
stand-alone PMPs with check valves and a vented receiver mounted on a common base. Duplex & Triplex systems can be used for increased capacity
or in the event of a single pump failure. All components of the system are properly sized and pre-piped together; requiring only four connections to
be made in the field. (see Complete Packaged Skid Systems)