ALLWEILER NBT Series Volute Thermal Centrifugal Pump
ALLWEILER NBT Series Volute Thermal Centrifugal Pump
ALLWEILER NBT Series Volute Centrifugal Pumps | Direct-Connected Circulation Solutions for Heat Transfer Oils and
High-Temperature Heat Media
ALLWEILER NBT Series Volute Thermal Centrifugal Pump Product Overview
The NBT series is a direct-connected volute centrifugal pump designed by ALLWEILER, a German company, specifically
for the circulation of organic heat transfer oils and high-temperature heat media. It features a block design and meets
DIN EN 733 standards. This series is one of the mainstay models in ALLWEILER's heat media pump product line, with
extensive application cases and an excellent reputation in the field of heat transfer oil circulation—some installations
have operated without failure for over 20 years.
ALLWEILER, a German pump brand with over 160 years of history (now part of the CIRCOR Group), has accumulated
profound technical expertise in the field of high-temperature heat media pumps. The NBT series differs structurally from
the NTT series (base-mounted) and NTWH series (flow-type design). It employs a direct-drive, block-type structure, with
the motor directly connected to the pump body via a flange or lantern bracket. This eliminates the need for couplings and
a common base, resulting in a smaller installation space and lighter weight, making it particularly suitable for applications
where installation space and cost are critical.
Series Positioning Comparison:
NBT Series: Direct-drive block design, for heat transfer oil only, up to 350°C, DN EN 733 standard
NTT Series: Base-mounted, for heat transfer oil only, up to 350°C, DN EN 733 standard
NTWH Series: Base-mounted, wide temperature range for heat transfer oil/synthetic oil/high-temperature hot water, up to 400°C
ALLWEILER NBT Series Volute Thermal Centrifugal Pump Core Technical Parameters
Parameter Item | Specification Range
Maximum Flow Rate | 270 m³/h
Maximum Head | 145 m (two-stage pump version)
Maximum Outlet Pressure | 16 bar (PN 10)
Maximum Medium Temperature | 350 °C
Speed | 2900 rpm / 1450 rpm (optional)
Connection Method | Flange connection (DIN standard)
Installation Method | Horizontal, direct-drive block design (motor connected via flange/lantern frame)
Design Standard | DIN EN 733 (formerly DIN 24255)
Applicable Media Organic heat transfer oil (thermal oil)
Electric motor (IEC standard motor)
ALLWEILER NBT Series Volute Thermal Centrifugal Pump Product Features and Design Advantages
1. Direct-Connect Block Design, Compact Structure
The NBT series adopts a direct-connect block design, where the motor connects directly to the pump body via a flange
or lantern frame, eliminating the need for couplings and a common base. This design offers several advantages: small
footprint, significantly saving installation space; lightweight, easy to handle and install; lower cost than base-mounted
installation solutions; and the option for horizontal or vertical installation, flexibly adapting to different site layouts.
2. Superior High-Temperature Resistance
Designed specifically for organic heat transfer oils, it can withstand media temperatures up to 350°C. The mechanical
seal is located behind the thermal barrier, effectively protecting the seals from high-temperature damage and extending seal life.
3. Compliant with DIN EN 733 Standards
The housing dimensions and rated output strictly comply with DIN EN 733 standards, ensuring good interchangeability
with mainstream pump models on the market.
4. Optional Two-Stage Pump Design
Within the same overall dimensions, the two-stage pump version offers a higher head, up to 145 m, particularly suitable
for applications requiring low flow rates and high head.
5. Proven High-Temperature Application Performance
The NBT series has received positive market feedback in high-temperature applications. For example, Ipsen International
GmbH, a leading global manufacturer of high-temperature furnaces, has been using NBT series pumps in its quenching oil
circulation systems since 1993, achieving over 20 years of trouble-free operation with no wear repairs or customer complaints.
Furthermore, the NBT series pumps are designed to exceed the safety requirements of DIN 4754 hot oil systems, featuring
additional safety elements to prevent large-scale liquid leakage in the event of mechanical seal failure.
6. Flexible Configuration Options
Supports various installation configurations to meet different site requirements: split configuration (motor and pump body
independent, base-mounted), direct-coupled block version (horizontal or vertical installation), and direct-coupled pipeline
version (vertical or horizontal installation). In addition, all pumps use IEC standard motors.
ALLWEILER NBT Series Volute Thermal Centrifugal Pump Core Application Areas
NBT series thermal oil pumps are widely used in the following industries and scenarios:
Application Areas Typical Scenarios
Heat Transfer Technology: Thermal oil boilers, heat medium circulation systems, community heating
Petrochemical Industry: Hydrocarbon preparation, reactor heating
Chemical Industry: Chemical preparation, hot fluid transportation
Rubber Industry: Vulcanizing machine heat medium circulation
Food Industry: Frying equipment, drying equipment hot oil circulation
Road Construction/Asphalt: Asphalt heating and insulation, storage tank circulation
Wood Industry: Drying kiln hot oil circulation
Shipbuilding/Marine Engineering: Marine hot oil systems
Heat Treatment Quenching Systems: Quenching oil circulation (e.g., Ipsen high-temperature furnace applications)
Applicable Media: Organic heat transfer oils (thermal oils)
Common Model Reference
The following are some common NBT series models (partial list):
ALLWEILER NBT Series Volute Thermal Centrifugal Pump Model | Specifications
NBT32-160 / 02U5A-W4-38/300 | Small diameter, 160 impeller
NBT32-160U5A-W4 | Standard configuration
NBT32-160/167U5A-W4-38/300 | Customized configuration
NBT32-160U5A-W4-28/250 | Customized configuration
NBT32-200/205 | 200 impeller series
NBT40-160 | 40 diameter series
NBT2/32-200/205U5A-W4-42/350 | Two-stage pump version
Model Explanation: The "NBT2/" prefix in the model (e.g., NBT2/32-200) indicates a two-stage pump structure,
meeting higher head requirements.
Installation and Maintenance Guide
Installation Precautions
Installation Location: Primarily horizontal installation, but vertical installation can also be chosen depending on site conditions.
Pipe Connections: Inlet and outlet pipes should be independently supported to prevent the weight of the pipes from acting
on the pump body flanges.
Pipe Cleaning: Thoroughly clean the inside of the pipes before installation to prevent impurities from entering the pump body.
Thermal Expansion: Under high-temperature conditions, it is recommended to install expansion joints at the inlet and outlet to
absorb thermal expansion.
Maintenance Recommendations
Regular Seal Inspection: Observe the mechanical seal for any signs of leakage.
Thermal Barrier Protection: The mechanical seal is located behind the thermal barrier; check the thermal barrier status during
maintenance.
Standby Pump Management: The standby pump should be periodically cranked to prevent jamming.
Safety Design
The NBT series pumps are designed to exceed the safety requirements of DIN 4754 for hot oil systems. In the event of mechanical
seal failure, additional safety elements ensure that only a small amount of liquid leaks, which can be collected and diverted without
causing damage. The special design of the insert unit reduces temperature, helping to extend the life of bearings and shaft seals.
Product Advantages Summary
Advantages Explanation
✅ German Quality: 160+ years of pump industry technology accumulation, a brand under the CIRCOR Group
✅ Direct-drive compact design: Saves installation space, no need for couplings or common bases
✅ Ultra-high temperature resistance: Can withstand up to 350°C for heat transfer oil
✅ Compliant with DIN EN 733 standard design, excellent interchangeability
✅ Two-stage pump option: Maximum head up to 145m, meeting high head, low flow rate requirements
✅ Mature track record: 20+ years of trouble-free operation in high-temperature furnace quenching oil systems
✅ Safety design: Exceeds DIN 4754 standards, with additional protection in case of seal failure
✅ Flexible installation: Horizontal/vertical options available, adaptable to different site conditions
✅ IEC standard motor: Convenient parts procurement
