Nikkiso canned motor pump

Nikkiso Non-Seal®
centrifugal canned motor pump

The NIKKISO centrifugal canned motor pump is specifically used in chemical industry for transfer and circulation tasks, particularly for supercritical fluids. The pump and motor are integrated in the sealed leak-proof structure of the centrifugal canned motor pump. The pump meets the specification of the API-685 standard.

In use, the centrifugal canned motor pump implements flow rates up to 1,200 m³/h and works with pressures up to 40 bar (at 50 Hz).

centrifugal canned motor pump

The NIKKISO centrifugal canned motor pump is an ideal solution for transfer and circulation tasks in the chemical industry. It can be used to pump hazardous, toxic and supercritical fluids.

The stator has a two-layer structure, consisting of the stator liner, stator band, and extremely tight terminal strip, allowing for a higher degree of safety. With the pressure raised by the impeller, the liquid is sent to the discharge side. A part of the fluid also reaches the motor and is used to lubricate the bearings and cool the motor of the centrifugal canned motor pump. Then, this part is lead back through the extraction openings on the shaft (standard model) for the intake side.

Good reasons for a NIKKISO Non-Seal® centrifugal canned motor pump

The NIKKISO Non-Seal is a compact centrifugal canned motor pump with integrated motor that covers high-pressure and high-temperature applications.

Integration of the motor

Directly integrating the canned motor into the centrifugal pump does not only ensure environmental protection, but also safety at the plant. All parts of the pump are also designed for easy and fast maintenance. Therefore, you can minimize unproductive down times.

Very good high-pressure characteristic

Compared to solenoid driven pumps, the NIKKISO Non-Seal centrifugal canned motor pump features considerably better high-pressure properties. Therefore, it is ideally suited for transfer and circulation tasks with critical or hazardous fluids.

High serviceability

Since the fluids lubricate the sliding parts, no additional lubrication is required. This gives the pumps a high degree of serviceability.

Low space requirement

Due to the integrated structure of the centrifugal canned motor pump, it only needs very little space and is ideal for applications in which a small footprint is required.

Quiet and low-vibration

The pump is quiet and has low vibration. It is extremely weather-resistant and has good dust protection.

Low maintenance costs

The pump has only low maintenance costs due to the relatively low number of components and the real-time monitoring of the bearing wear.


API and ATEX conformity

Nikkiso centrifugal canned motor pumps comply with API 685 standards and ATEX directives and can be used for the production of most liquids in the oil and chemical industries.

Remote display for remote control

Security is the Alpha and Omega: That's why we offer the option of an integrated remote display including alarms and emergency shutdown for your canned motor pump.

Bearing monitoring

A proper process monitoring not only prevents failures, it also ensures a long lifetime of pump. To support this, we recommend at least a mechanical bearing monitoring system for the canned motor pump.

DIN EN ISO 2858 – End-suction centrifugal pumps (rating 16 bar)

NIKKISO centrifugal canned motor pumps meet the dimensions and nominal outputs in accordance with DIN EN ISO 2858. This means that NIKKISO fulfills the requirements of a standardized chemical pump, which makes it easier to exchange existing pumps.

Dry-run safe

We ensure that your centrifugal canned motor pump is running as properly as possible. The Nikkiso SAO relay detects a dry-run of the pump. This provides for proper and safe operation and prolongs the service life of the pump.

Optional inducer

To improve the suction conditions (NPSHR), the Nikkiso centrifugal canned motor pumps can be equipped with an inducer.

Examination by experts and authorities

We also gladly provide performance diagrams and certificates of static pressure tests also by TÜV, Germanischer Lloyd’s, Lloyd’s R. of S. or other authorities.

Assembly on site

From engineering to commissioning – all from a single source: Our systems are suitable for sea transport and can be completely disassembled and reassembled at the destination.

Dip tank

LEWA supplies the required accessories from a single source. For the HM pump type, a dip tank is available for feeding the rinsing liquid to the mechanical seal.

Performance data

The NIKKISO Non-Seal centrifugal canned motor pump is available in Standard and Engineered Design.

Technical data

  Standard Design Engineered Design
Flow rate max.: 780m³/h (3430 gpm) 1200 m³/h (5280 gpm)
Pump head max.: 210m (688ft) 600 m (1,970 ft)
Fluid temperature range -50 to 350°C (-58 to 662°F) -200 to 450 °C (-328 to 842 °F)
Density range 0.3 to 2.0 Max. 13.6
Viscosity max. 200 mPa∙s (200 cP) 500 mPa∙s (500cP)
Working pressure max. 4 MPa (600 psig) 80 MPa (11,600 psig)
Liquid end material SUS316, SUS304 Alloy 20, Hastelloy C/B, titanium, zirconium, etc.
Motor power range 0.4 to 132 kW (0.5 to 177 metric horsepower) 200 to 250 kW (268 to 335 metric horsepower)
    * "Hastelloy" is a registered trademark of Haynes International, Inc.

Pump types

We provide different pump models for different applications. Here, the spectrum ranges from all-purpose variants to special designs for high temperatures, pressures or aggressive fluids.

Basic (N)

The pump and motor are connected by an adapter plate or a FB housing. A portion of the liquid being pumped is taken from the impeller outlet part of the pump chamber into the rotor chamber for the purposes of cooling the motor and lubricating the bearings. Then, the fluid is returned to the pump chamber through the hollow shaft. A cooling jacket may be fitted to the outer wall of the stator assembly depending on the temperature and other characteristics of the liquid being pumped.

Circulation Boost Basic (V)

The cross-sectional dimensions are the same as those of the basic design (N type), but the return passage is wider to maintain a return flow of liquid when handling high-viscosity (80 to 200 mPas) liquids.

High temperatures (T)

Pump and motor are connected with an adapter. The adapter separates the pump thermally from the motor and prevents heat transfer from the pump to the motor. In the design for high temperatures, an independent circulating system is provided for motor cooling and bearing lubrication. Circulation is effected by the auxiliary impeller located at the front end of the rotor chamber. A heat exchanger is fitted to the outer wall of the stator assembly to cool the circulation liquid.

High temperatures, without cooling (HX)

The HX type is intended for pumping liquids with high temperatures. Cooling is not required when using a special ceramic motor insulation. The HX type can be installed with a heating jacket and is well suited for handling high melting point liquids (above 140 °C) which exceed the temperature limit of normal organic motor insulation materials.

Slurry handling (S)

The basic construction is identical to that of the pump version for high temperatures. The function of this arrangement is to prevent the slurry handled from entering into the rotor chamber. Clean liquid compatible with the liquid that is pumped is flushed from the inlet port on the rear of the motor to prevent slurry from entering into the rotor chamber. Normally, a backflushing line would be required for this.

Mechanical seal when handling slurry (M)

A design is also available with a mechanical seal between the pump and motor due to the requirement of decreasing the amount of liquid used for backflushing. This pump type is called a slurry handling pump with a mechanical seal (M type). The backflushing volume can be decreased to 100 ml/day to 500 ml/day.

Slurry handling, gas seal (LG)

A gas seal type is also available that is suitable for handling heavily corrosive liquids, liquids liable to polymerize or liquids with a high concentration of slurry. The construction is nearly identical to that of the slurry handling pump with mechanical seal listed above. The special feature of this pump type is that a gas chamber is located between the pump unit and the motor unit. The gas chamber separates the pump unit from the motor unit completely. This prevents the risk that the mechanical seal wears out or corrodes through the pumped liquid. Like the backflushing liquid (100 ml/day to 500 ml/day), clean original liquid or clean liquid can be mixed with the pumped liquid if only a very small amount is used. Also, because gas collects in the gas seal chamber, for example, air can be used on nitrogen.

High melting point (B)

This pump has a construction suitable for liquids with a high solidifying point. It is provided with a heating jacket on the outer face of the pump and the motor to prevent liquid from solidifying at a time of the liquid filling and during the pump operation.

Liquid recirculation (Q)

The notable feature for this pump is that the circulation line does not form a closed circuit. The coolant for motor and bearings flows through the rotor chamber and is fed back through the outlet of the rear bearing housing at the rear of the motor to the suction tank. With the basic model of the centrifugal canned motor pump (N), a liquid with a low boiling point would evaporate after passing through the rotor chamber due to temperature increase and cause a cavitation.

Self-priming pump, horizontal (DN)

The underlying structure is identical to the basic design. This pump type is designed so that the pump is self-priming even without a flap valve present. Since there is no flap valve, heavily corrosive liquid can also be handled; in addition, there is no possibility of poor self-priming due to a blockage in the flap valve.

Low flow rate; higher head and high speed (HK)

The HK type is designed for handling easily evaporating fluid without additional reverse circulation line piping. This pump can maintain higher pressure than the vapor pressure in the motor chamber, thereby preventing evaporation. If you would like to find out more about the HK pump type, please contact us.


Efficient operations in high head applications.


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