Water Passage Design
MTH masters one of the most critical design
considerations of regenerative turbine pumps - the shaping of water
passageways to achieve maximum capacity and pressure while minimizing
horsepower requirements. By optimizing water passageway cross-sectional
profiles for each impeller, MTH improves both efficiency and pressure
in the M50 Series, and exceeds the standards realized by previous
One of the most notable improvements in regenerative
turbine pump technology, incorporated in M50 Series pumps, involves
the ability to determine the optimum impeller width and blade length.
These factors have a significant effect on the required horsepower
versus pressure curve for regenerative turbine pumps. By optimizing
these for each pump, peak efficiency is improved and "off peak"
horsepower requirements are reduced as well.
After the most favorable impeller profile has
been determined for a particular water passageway cross-section,
MTH calculates the number of blades needed to maximize the performance
of that pump. The blade design in M50 Series pumps increases both
efficiency and design pressure without incurring the manufacturing
difficulties associated with producing contoured blade impellers.
State-of-the-art computer controlled machines simplify manufacturing
of the various MTH impellers utilized in the M50 Series. The result
is a high performance pump providing efficiency characteristics
exceeding those of much more expensive units.
M50 • L50 Series regenerative turbine
pumps meet low net positive suction head (NPSH) requirements without
efficiency loss. This is achieved by keeping the inlet fluid velocity
low and then gently accelerating to passageway velocities. Special
ramps are responsible for this gentle fluid entry into the impeller
blades and account for the high inlet efficiency of the M50 •
L50 Series pumps.
Low NPSH Requirements
L50 Series regenerative turbine pumps have exceptionally
low NPSH requirements, making them ideally suited for applications
where very little inlet head is available.
This reduced NPSHR provided by the L50 Series is obtained
by using a first stage centrifugal style impeller with inlet
flow paths shaped to maintain a constant fluid velocity. This
reduces entry losses to the impeller as well as maintaining
efficiency. A multi-vane diffuser is used in conjunction with
the centrifugal impeller for balancing radial loads and extracting
the maximum pressure from the first stage. Pressure and flow
produced by the NPSH inducer assures that the succeeding stages
are adequately fed.