WEFTEC 2005

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WEFTEC 2005
TORUS vs. cup type and other radial vane designs
Analysis of recessed impeller pump designs.
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Typical Recessed Impeller Pump Configurations
Vertical Dry Pit
Horizontal Dry Pit
Submersible
Vertical Cantilever
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Recessed Impeller Pump Designs
There are heavy duty, medium duty and light duty
recessed impeller designs. For hard abrasives
applications like grit and primary sludge only
the heavy duty designs should be used.
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Recessed Impeller Pump Designs Heavy Duty
Suitable pump designs are the Hayward Gordon XR
series, Wemco Model C, Morris/Goulds 6100 series.
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Recessed Impeller Pump Designs Medium Duty
Hayward Gordon R Series
Model CE
These pumps are best suited for non-clog pumping.
They have hard metal construction and relatively
thick casing sections so will stand up better
than light duty designs. The TORUS R series has
a replaceable wear element the Wemco Model CE
does not.
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Recessed Impeller Pump Designs Light Duty
Wemco Model E
Marlow Whirl-Flo
Goulds HS
Aurora 661
Light duty designs are suitable for non-clog
pumping. Should not be used when hard abrasives
are present. These pumps have thin casing
sections and have no replaceable wear element.
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Understanding hydraulics through
recessed Impeller pumps.
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Vortex Flow Patterns - Radial Vane Impeller
Predetermined Area of Maximum Wear - flow from
open radial vanes is directed towards the area
around the impeller periphery. SACRIFICIAL WEAR
ELEMENT HERE.
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Vortex Flow Patterns - Cup Type Impeller

• Predetermined Area of Maximum Wear - flow from
  impeller is directed at front of casing.
  SACRIFICIAL WEAR ELEMENT HERE.

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Wemco Model CE
Vortex Flow Patterns - Cup Type Impeller

• Two Step Wear Mechanism Evens Out Wear. ???
• 4 CE is half the weight of the 4 Model C

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Standard radial vane designi.e. Goulds HS or
Marlow Whirl-Flo no sacrificial wear element
to protect casing casting sections
are thin
Vortex Flow Patterns - Radial Type Impeller
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TORUS Recessed Impeller Pump
Review of Hayward Gordon XR series
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TORUS Pump - Impeller Wear Element
Thick radial vane impeller
Heavy duty wear ring. You have to wear through
this before you even get to the casing!
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TORUS Recessed Impeller Pump

• Heavy duty volute casing

Inspection photo after 28,000 hours no sign of
scouring or wear on front of casing
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TORUS vs. Model C

• Over hung casing not as easy to work on
• Impeller bore not machined difficult to work
  on and dangerous if trying to remove impeller
  through suction piece.
• Cast iron pedestal flange exposed to the flow

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Competition Comparison of 4x15 Models
Wemco
Wemco
Hayward Gordon

• Foot mount VS overhung casing

• Rugged powerframe and generous shaft diameter

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Vortex Pump Impeller Styles
Cup type impeller Impeller cant be trimmed
only offered as horizontal dry pit
Radial vane impeller Impeller can be trimmed so
suitable for submersible or direct drive designs
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Spare parts requirements
Three (3) wet end primary wear components
impeller, suction piece, back plate/wear ring.
Only two (2) wet end primary wear components
impeller and back plate/wear ring
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TORUS vs. Model CE
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TORUS vs. Model CE

• Over hung casing not as easy to work on
• No replaceable sacrificial wear components.
• - Much lighter in weight than TORUS and Model C
• - Suitable for general sludge applications
• - Equivalent efficiencies to that of the TORUS
• - Excellent non-clog design (same as any other
  recessed impeller pump)