• Stainless Steel Wetted Parts for Excellent Chemical Compatibility
• Standard NPT Threads with optional ISO, BSP, and SAE Available
• Conduit or Electrical Junction Box
• Variable Frequency Drive / Transducer Package Optional
The X41 Series line of sealless regenerative turbine
pumps (also known as canned, hermetic, or zero emission pumps)
is designed to handle applications with difficult to seal fluids
where absolutely leak free performance is required, and mechanical
seals simply cannot provide the needed reliability, protection,
and performance. All of this is accomplished at a price point
previously unseen in the industry, and is often comparable with
other mechanically sealed solutions, but without the leaks and
inevitable seal maintenance. Water/glycol mixtures and exotic
heat transfer fluids present no difficulty for these units at
fluid temperatures from -84°C up to 150°C. The canned
motor design is far preferable to magnetic drive couplings as
it does not add excessive length to the unit in tight OEM enclosures,
or suffer from the magnetic de-coupling problems often associated
with mag-drive solutions. Three bearings, high strength cast stainless
steel components, and a sealless design assure extended maintenance
free life. To demonstrate the potential reliability of these units,
well over 800 X41's have been shipped into the field from 1997
thru 2003 into water/glycol chiller applications. Of these 800+
units at end user sites, none have yet been reported to the factory
as failed, leaking, or requiring any repair. For other special
fluids and applications, optional elastomers, electrical connections,
and variable frequency drive control packages are all available
to custom fit your particular needs.
*Current X41 models are based on the T41 Series
mechanically sealed pump hydraulics, while the future X51 models
based on the T51 Series are available
upon special request for higher capacities and pressures.
The hermetically sealed pump/motor combination uses the process
fluid itself for cooling, while a stainless steel barrier keeps
the fluid isolated from the stator wire and rotor. A ceramic potting
material is used to back up this .015 inch thick barrier to provide
mechanical strength under high operating pressures. This special
potting material is electrically insulating and also has the property
of being highly heat conductive to help dissipate excess heat.
Each and every pump is tested for barrier and containment integrity
Optional inlet/outlet threading is available to match your system
design needs. NPT threads are standard for North American usage
for compatibility with low cost, commonly available pipe fittings.
BSP is available for use with commonly available pipe fittings
in England and associated countries, while ISO is used for applications
where compatibility with international standards is important.
SAE threads are also available for use where the most highly reliable
leak-free connections are required.
The pump/motor units use three carbon bearings, with the motor
rotor positioned between two thrust bearings, and the impeller
supported on both sides to provide long running life. As with
all plain bearing pumps, keeping pumping systems free of solids
to prevent premature bearing failure is important. The X Series
is, however, designed with easily replaceable bearings that can
be changed out in a matter of minutes, providing a low cost means
of maintaining "like new" performance over long periods.
Specialized bearing materials are continuously being tested as
new applications arise to allow further extension of useable life
in harsh pumping applications. The rotor shaft bearings, as well
as the turbine impeller, are easily replaced during scheduled
maintenance events when used under severe operating conditions.
Like its T41 Series mechanically sealed counterpart, the X Series
hydraulic passageways are designed to minimize thrust on the self-adjusting
impeller to avoid upsetting its hydraulic balance, and to handle
low NPSH conditions which can occur in some applications. New
to the X Series is the location of the inlet and outlet on the
centerline of the impeller to further eliminate the potential
of axial imbalance that sometimes occurs during periods of marginal
NPSH availability. With these design features, MTH has eliminated
almost all of the bearing thrust loads in these units, and the
motor thrust bearings exist only to provide axial rotor positioning.
Vent/drain taps are provided on both ends of the pump/motor unit
to facilitate draining or air purging of the unit in either the
horizontal or vertical position. Proper air purging at startup
will help assure that the bearings are properly lubricated and
minimize startup wear and priming problems. SAE fittings are used
for both of these openings to assure a reliable leak-free fit,
and to minimize the potential of galling that can be troublesome
if over-tightening should occur.
All models feature top centerline suction and side discharge for
best inlet conditions. The entire unit can be rotated every 90°
to allow different inlet/outlet positions while maintaining best
fluid entry, particularly when suction pressures are approaching
the vapor pressure of the pumped fluid. There are no orientation
restrictions when installing these pumps. Vertical mounting (pump
up or down) has no effect on the unit's operation. This ability
to mount the pump in any position gives the customer added flexibility
in the design of their system.
Compactness also favors these canned motor pumps over magnetic
drive pumps. In fact, most models are no larger than their equivalent
close-coupled mechanically sealed pump/ODP motor cousins.
The X Series should be considered for applications where leakage
cannot be tolerated. The sealless design ends down time and maintenance
problems associated with mechanical seal pumps.
The compact size fits most OEM situations where close-coupled
ODP motor/pumps will fit. These pumps can be easily mounted vertically,
with the pump end up using the motor end cap as the base, or horizontally,
using a standard or special mounting bracket, as necessary, to
fit each application.
The X Series has fewer parts than most pump/motor combinations,
which translates into easy assembly/disassembly for maintenance,
and for lower manufacturing costs which ultimately means a lower
price to the customer.
All rotating parts are enclosed, reducing ambient noise. No
fans or ball bearings, which are typically sources of noise, are
used. These pumps are exceptionally quiet due not only to their
"plain bearing" design, but also because of refinements
in the water passage hydraulics. This essentially eliminates the
"high pitched whine" that has previously been associated
with regenerative turbine pumps.
The sealless canned motor design offers significant advantages
over magnetic drive solutions. The X Series pumps are actually
integrated into the motor housing to provide a very compact package
that eliminates the excess space requirement for a coupling, which
is often critical in tight OEM enclosures. This design is also
more reliable in that it has fewer parts and does not suffer from
the magnetic de-coupling problems or degradation that often occur
without warning in mag-drive units.
All standard X Series pump models have a 316 stainless steel
housing and a non-galling Waukesha 88 impeller. The Waukesha 88
alloy contains 70% nickel which is typically more corrosion resistant
than 316 stainless steel in most chemical applications.
A wide variety of "O" ring materials are available
so the pump can be compatible with almost any fluid. Viton, EPR,
Buna, Teflon, Kalrez, and other specialized materials can be made
available to suit the application.
Bearings made of various carbon combinations are compatible
with most fluids, while other bearing materials are available
for testing in special applications upon request. The three bearings
provide a large area for ample support of loads and long bearing
The selected motor insulation allows operation in high temperature
applications. Windings are suitable for operation at temperatures
of 200°C (392°F) and utilize NEMA Class N inverter grade
insulation for use with variable frequency drives and to provide
the longest life under all operating conditions.
Variable Speed Option
X Series pumps are available with an optional variable
frequency controller and a pressure transducer in a completely
assembled and tested unit. A closed loop pressure transducer /
variable frequency drive combination can eliminate the need for
costly pressure relief valves and their associated plumbing problems,
while gaining the ability to maintain constant discharge pressure
by automatically varying pump motor speed. Signal inputs and outputs
are available on the drive for accommodating a variety of external
controls, alarm set point signals, and other programmed outputs.
This package is particularly helpful to OEM manufacturers whose
equipment is exported to countries utilizing 50-Hertz electrical
supply systems. The drive can take inputs at 50 or 60Hz at a number
of different voltages, and produce a variable frequency and voltage
output suitable for pump output requirements, without any rewiring
or user intervention required. This is a significant step forward
in the design of a truly power source independent, worldwide product.
Variable frequency controller / transducer packages are also available
for customer applications where flow, temperature, or other variables
need to be maintained. Please consult the factory for further
information on these options.
other MTH products, 100% of X Series pumps are tested for proper
operating characteristics before shipment. For specially requested
longer term testing, a facility is available to simulate actual
customer applications. MTH can operate a pump under the customer
specified conditions for periods of time necessary to extrapolate
minimum service life, recommended service intervals, MTBF, or
other information. Testing quotations and proposals are based
on the complexity of the required test, and with any special fluids
being supplied by the customer.
Composite Curves: Models X41B thru X41J
Find your service point on the graph below and click to see the
individual performance curve. Click for ENGLISH