ALLWEILER NTT series thermal oil pumps

The ALLWEILER NTT series is a horizontal volute centrifugal pump designed by ALLWEILER GmbH of Germany specifically for heat transfer oil and high-temperature heat medium circulation systems. This series features a base-mounted design and meets DIN EN 733 / EN 733 standards, representing a recognized high-temperature fluid transport solution in the field of heat transfer technology.

ALLWEILER, a German pump brand with over 150 years of history (now part of the CIRCOR Group), has accumulated profound technical expertise in the field of high-temperature heat transfer pumps. Its NTT series products are widely used in various industrial sectors, including petrochemicals, textile dyeing and finishing, food processing, rubber industry, road construction and asphalt, community heating, and shipbuilding and marine engineering.

ALLWEILER NTT series thermal oil pumps Model Description: 

The NTT series adopts the German standard naming convention. Taking NTT 65-250 U5A-W4 as an example:

Code Location | Meaning | Example Interpretation

NTT Pump Series Code | NTT = Volute Centrifugal Pump, for Heat Transfer Oil

65 Nominal Discharge Diameter (mm) | DN 65

250 Nominal Impeller Diameter (mm) | Φ250 mm

U5A Seal Code | Unbalanced Mechanical Seal with Safety Stuffing Box (Self-Cooling Design)

W4 Material Code | Cast Iron Material Combination (Suitable for Non-Corrosive Heat Transfer Oils)

Available Specifications (Partial List):

Model | Suction Port Diameter DN | Discharge Port Diameter DN | Impeller Diameter (mm)

NTT 32-160 | 32 | 32 | 160

NTT 32-200 | 32 | 32 | 200

NTT 32-250 | 32 | 32 | 250

NTT 40-160 | 40 | 40 | 160

NTT 40-200 40 40 200

NTT 40-250 40 40 250

NTT 50-160 50 50 160

NTT 50-200 50 50 200

NTT 50-250 50 50 250

NTT 65-160 65 65 160

NTT 65-200 65 65 200

NTT 65-250 65 65 250

NTT 80-200 80 80 200

NTT 80-250 80 80 250

NTT 100-160 100 100 160

NTT 100-200 100 100 200

NTT 100-250 100 100 250

Note: More than ten specifications are available, ranging from NTT 32-160 to NTT 100-250, covering applications from low 

to high bandwidth.

Core Technical Parameters

Parameter Item | Specification Range

Maximum Flow Rate: 1250 m³/h

Maximum Head: 145 m

Maximum Medium Temperature: 350 °C (Heat Transfer Oil/Heating Medium Oil)

Maximum Outlet Pressure: 16 bar (PN 16)

Speed: 2900 rpm / 1450 rpm (Optional)

Connection Method: Flange Connection

Pump Body Material: Ductile Iron (JS1025) / Cast Iron

Impeller Material: Cast Iron (JL1020)

Shaft Material: Chrome Steel (1.4021)

Bearings: SKF / Metal Rolling Bearings

Sealing Type: Single-End Mechanical Seal (with Safety Stuffing Gland) / Double Seal Optional

Installation Method: Horizontal, Base Mounting

Motor: ABB / Siemens / Teco, etc. (Optional)

ALLWEILER NTT series thermal oil pumps Product Features and Design Advantages

1. Superior High Temperature Resistance

Designed specifically for organic heat transfer fluids (heat transfer oil), it can withstand media temperatures up to 350°C. Optimized

 thermal barrier design effectively isolates high temperatures from the pump body to the bearings and motor, ensuring long-term

 stable operation.

2. Self-Cooling Maintenance-Free Sealing System

Utilizing a combination design of a single-end mechanical seal and a safety stuffing box (such as U5A), it can operate reliably under 

high-temperature flexible conditions without external cooling water. This design significantly reduces operating costs while avoiding

 scaling and clogging problems that can occur with water-cooled systems.

3. High-Efficiency and Energy-Saving Design

Optimized hydraulic model ensures leading pump efficiency.

The impeller can be trimmed according to the customer's actual operating point, eliminating unnecessary energy consumption.

Energy savings of over 10% compared to conventional hot oil pumps.

4. Convenient Maintenance

Removable bearing brackets and a back-extraction design allow the entire rotating component (impeller, shaft, bearings, seals) to

 be removed without disassembling the pump casing, significantly reducing maintenance time.

5. Rigorous German Manufacturing Process

Thick pump cover and optimized bearing system design ensure long-term operational reliability.

Optimized pump shaft profile design effectively prevents leakage and ensures high reliability.

Rated pressure up to 25 bar (special specifications)

6. Flexible Configuration

Optional ATEX explosion-proof type (suitable for hazardous areas)

Optional DNV-GL classification society certification (marine and marine engineering)

Selectable speeds of 2900 rpm / 1450 rpm to adapt to different operating conditions

NTWH/CTWH series high-temperature models (up to 400℃) are available.

ALLWEILER NTT series thermal oil pumps  Core Application Areas

NTT 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, distillation tower reboilers

Textile Dyeing and Finishing | Stenter, dryer thermal oil circulation

Food Industry | Frying equipment, drying equipment hot oil circulation

Rubber Industry | Vulcanizing machines, rubber mixing equipment hot oil circulation

Road Construction/Asphalt | Asphalt heating and insulation, storage tank circulation

Chemical Industry | Chemical preparation, hot fluid transportation

Detergent/Soap | Production line hot oil transportation

Wood Industry | Drying kiln hot oil circulation

Shipbuilding/Marine Engineering | Marine hot oil systems (DNV-GL certification available)

Oil and Gas Industry | Hydrocarbon handling, hot oil transportation

ALLWEILER NTT series thermal oil pumps Product Advantages Summary

Advantages | Description

✅ German Quality: 150+ years of pump industry technology accumulation, manufactured in Germany.

✅ Ultra-high Temperature Resistance: Withstands up to 350°C for heat transfer oil (NTWH series up to 400°C).

✅ Self-Cooling Seal: No external cooling water required, reducing operating costs and simplifying installation.

✅ High Efficiency and Energy Saving: Optimized hydraulic model, impeller can be cut to match actual working conditions, saving 

10%+ in energy.

✅ Convenient Maintenance: Back-pull design, maintenance without disassembling the pump casing.

✅ Base Mounting: Pump and motor are mounted together on the base, stable structure, easy installation.

✅ Flexible Configuration: Multiple specifications and sealing options, ATEX/DNV-GL optional.

✅ Complete Diameter Range: DN 32 – DN 100 full coverage, flow rate 3-1250 m³/h.

Installation and Maintenance Guide

Installation Precautions

Installation Location: Install horizontally, ensuring concentricity between the pump and motor.

Pipe Connections: Inlet and outlet pipes should be supported to prevent weight from acting on the pump body.

Expansion Joints: Expansion joints are recommended at the inlet and outlet for high-temperature operation to absorb thermal expansion.

Flow Direction Confirmation: Confirm that the flow direction arrow on the pump body matches the pipe direction.

Maintenance Recommendations

Regular Seal Inspection: Observe for any signs of leakage; address any abnormalities promptly.

Bearing Lubrication: Regularly check the lubrication status of the drive-end bearings.

Impeller Inspection: Inspect the impeller wear according to the operating cycle.

Seal Replacement: Replace the mechanical seals according to the manufacturer's recommended replacement cycle.

Why Choose Us?

Direct Source: 100% Genuine ALLWEILER Products from the German factory.

In Stock: We maintain a large inventory of commonly used specifications for fast delivery.

Full Model Coverage: Complete range of sizes from DN 32 to DN 100.

Fast Delivery: In-stock orders can be shipped quickly.

Professional Technical Support: We provide selection guidance, installation, commissioning, and after-sales service.

Original Warranty: 1-year warranty under normal use.

Important Note: This product is a genuine ALLWEILER product from Germany. Please look for the brand logo. Using non-original 

substitutes may result in substandard performance, seal failure, and other safety hazards.