KF32 KF40 KF50 KF63 KF80 KF112 KF125 KF200 KRACHT Gear Pump 25 bar

Product Overview

The KF32, KF40, KF50, KF63, KF80, KF112, KF125, KF200, as well as KF180RF1 and KF200RF1 series gear pumps originate from Germany’s KRACHT KF Series helical transfer pump platform. KRACHT is a family-owned enterprise founded in 1911, headquartered in Werdohl, Germany, and a world-renowned specialist in fluid control. The KF Series is KRACHT’s classic medium-low pressure transfer pump product line, renowned for helical gearing, low pulsation, low noise, and modular design – widely used in wind power, marine gearbox lubrication, compressor lubrication, and other long-term continuous operation heavy-duty applications.

This series features helical external gear pump construction with a modular standard design. Housing parts are manufactured from EN-GJL-250 (GG 25) grey cast iron or EN-GJS-400-15 (GGG 40) ductile cast iron. Gears are made from 1.7139 high-strength case-hardened steel, hardened and mounted in multi-compound plain bearing bushes. All sizes are made with helical gearing, which, in combination with a special gearing geometry, results in extremely low noise levels and low-pressure pulsation.

Key Interchangeability Advantage: Our KF series gear pumps are manufactured to strict German KRACHT original design specifications, ensuring 100% direct interchangeability with original units. All mounting interfaces (DIN ISO 3019 flange), shaft configurations, and port positions are identical to the original product – no modifications required. Every pump undergoes 100% factory performance testing under simulated operating conditions (covering rated pressure, peak pressure, and full speed range performance curves), guaranteeing plug-and-play reliability with zero performance deviation.

Important Note: Pressure Grade Distinction

⚠️ The KRACHT KF Series includes both low-pressure transfer pumps and high-pressure gear pumps:

• Low-Pressure Transfer Pump (KF Standard Series) : Standard operating pressure 25 bar, peak 40 bar – corresponding to standard models KF32, KF40, KF50, KF63, KF80, KF112, KF125, KF180RF1, KF200RF1

• High-Pressure Gear Pump (KP Series) : Continuous operating pressure up to 300 bar – corresponding to KP0, KP1, KP2, KP3, KP5 series

The KF32–KF200 standard models and KF180RF1/KF200RF1 queried by the user belong to the low-pressure transfer pump series, suitable for lubrication, transfer, circulation, and other low-pressure applications. Some e-commerce platforms may list the KF Series as “high pressure” for marketing categorization, not as a technical specification.

Model Code Breakdown (based on KRACHT KF Series designation rules):

• KF = Series: Helical Transfer Pump

• 32 / 40 / 50 / 63 / 80 / 112 / 125 / 180 / 200 = Nominal displacement (cm³/rev)

• RF1 / RF2 / LF1 = Mounting type (RF: flange mounting right-hand / LF: flange mounting left-hand)

• D15 (optional suffix) = Integral relief valve, set pressure approx. 15 bar for overload protection

Technical Specifications 

KF Series – General Specifications

• Product Series: KRACHT KF Series Helical Transfer Pump

• Brand: KRACHT (Germany)

• Pump Type: Helical External Gear Pump

• Displacement Range: 2.5 – 3150 cm³/rev

• Maximum Operating Pressure: 25 bar

• Peak Pressure: Up to 40 bar

• Media Temperature Range: -40°C to +200°C

• Media Viscosity Range: 12 – 20,000 mm²/s

• Inlet Pressure: -0.4 to 2 bar

• Housing Material: EN-GJL-250 (GG 25) grey cast iron or EN-GJS-400-15 (GGG 40) ductile cast iron

• Gear Material: 1.7139 high-strength case-hardened steel

• Bearings: Multi-compound plain bearings P10 / DP4 (DU bushings)

• Seals: NBR, FKM, low-temperature FKM

• Shaft Sealing: Single radial lip-type seal

• Mounting: Flange mounting (DIN ISO 3019)

• Direction of Rotation: Bidirectional (left-hand or right-hand selectable)

KF32 Series

• Displacement: 32 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 1½” SAE flange

KF40 Series

• Displacement: 40 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 1½” SAE flange

KF50 Series

• Displacement: 50 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 1½” SAE flange

KF63 Series

• Displacement: 63 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 1½” SAE flange

KF80 Series

• Displacement: 80 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 1½” SAE flange

KF112 Series

• Displacement: 112 cm³/rev

• Speed Range: 200 – 3000 r/min

• Port Connection: 2″ SAE flange

KF125 Series

• Displacement: 125 cm³/rev

• Speed Range: 200 – 3000 r/min

• Weight (with valve): Approx. 27.5 kg

KF180RF1

• Displacement: 186.6 cm³/rev

• Maximum Operating Pressure: 25 bar

• Peak Pressure: 40 bar

• Speed Range: 200 – 3000 r/min

• Noise Level: ≤ 69 dB(A)

• Shaft Diameter: 28 mm

• Weight: 27.5 kg

• Direction of Rotation: Right-hand (RF1)

KF200 / KF200RF1

• Displacement: 200 cm³/rev

• Maximum Operating Pressure: 25 bar

• Peak Pressure: 40 bar

• Speed Range: 200 – 3000 r/min

Key Technical Advantages

1. Helical Gear Design for Ultra-Low Noise and Low Pulsation

All KF Series sizes feature helical gearing combined with a special gear geometry, effectively reducing displacement fluctuation and pressure pulsation. Pressure pulsation is extremely low, with operating noise as low as 69 dB(A). This characteristic makes it particularly suitable for lubrication systems with strict noise and flow stability requirements – especially in wind turbine gearbox lubrication and marine lubrication applications with stringent noise demands.

2. High-Strength Materials and Composite Plain Bearings for Long Service Life

KF Series housings are manufactured from EN-GJL-250 (GG 25) grey cast iron or EN-GJS-400-15 (GGG 40) ductile cast iron. Gears are made from 1.7139 high-strength case-hardened steel. Combined with multi-compound plain bearings P10/DP4 (DU bushings), the design delivers excellent wear resistance, rugged construction, and impact resistance. The very robust design ensures long service life across all operating conditions.

3. Wide Media and Temperature Adaptability for Wind Power and Marine Applications

The KF Series offers a media temperature range of -40°C to +200°C with broad viscosity adaptability (12 – 20,000 mm²/s). The -40°C low-temperature capability makes it the ideal choice for wind power low-temperature lubrication systems. Multiple seal options (NBR, FKM, low-temperature FKM) are available to meet diverse media requirements.

4. Modular Design and Flexible Configuration

The KF Series features a modular standard design, with displacement, flange, shaft end, rotation direction, and seal materials all customizable. Optional Type D integral relief valve (D15) provides overload protection for both pump and system. Optional ATEX explosion-proof versions, noise-optimized versions, and outboard bearings for absorbing radial loads are available. The mounting position can be chosen arbitrarily.

5. Wide Displacement Coverage for High-Flow Lubrication Requirements

The KF Series offers displacements from 32 to 200 cm³/rev (with additional options up to 125, 180, 200 cm³/rev and beyond). The KF180RF1 delivers 186.6 cm³/rev displacement, meeting the oil supply demands of high-flow lubrication, cooling, and transfer systems. The KF 4…112 Series, as positive displacement pumps, is suitable for continuous fluid delivery.

Application Areas

• Wind Power: Wind turbine gearbox lubrication systems

• Marine Gearbox Lubrication: Lubricating oil supply for marine gearboxes

• Compressor Lubrication: Compressor lubricating oil supply

• Diesel Engines: Pre-lubrication and main lubrication

• Filter Systems: Oil delivery and circulation

• Fuel Delivery: Fuel supply systems

• Industrial Lubrication Systems: Reducer lubrication, sugar and alcohol industry, mining, pulp and paper, turbines and generators, machine bearing lubrication

• Process Technology: Metering pump low-pressure feed, recirculation pumps, filling pumps, feed pumps for piston pumps

Expert Maintenance Tips

1. Model Confirmation and Selection

• Complete KF series model should include: Series (KF) + Displacement Code (32–200) + Mounting Configuration (RF1/RF2/LF1) + Optional Suffix (D15 with valve) .

• RF1 indicates flange mounting, right-hand rotation; RF2 indicates flange mounting, right-hand (specific configuration); LF1 indicates flange mounting, left-hand rotation.

• The KF Series is for low-pressure transfer (standard 25 bar, peak 40 bar). For high-pressure applications (up to 300 bar), select the KRACHT KP Series.

• KF32–KF112 feature 1½” SAE flange connections; KF100/KF112 feature 2″ SAE flange connections. Verify port connection specifications during selection.

2. Pre-Installation Checks

• KF Series pumps are bidirectional – select left-hand or right-hand rotation as required. Verify matches system drive direction before installation.

• Confirm mounting flange type (DIN ISO 3019 flange) precisely matches system interface.

• Inlet pressure must be maintained within -0.4 to 2 bar.

• Never use hammer-driven installation – always use proper tools.

3. First Start-Up & Media Priming

• Prime the pump housing with clean media before first start-up; ensure suction line is fully filled – never run dry.

• Maintain media temperature within -40°C to +200°C.

• Speed range: 200 – 3000 r/min.

• Media viscosity should be maintained within 12 – 20,000 mm²/s.

4. Integral Relief Valve Usage Notes

• If equipped with D15 integral relief valve, the valve is for overload protection only – do not operate in continuous relief mode. For prolonged partial discharge flow, a separate pressure relief valve with return line must be installed in the system.

5. Operating Monitoring

• Continuous operating pressure must not exceed 25 bar; peak pressure must not exceed 40 bar.

• The KF Series is known for low noise and low pulsation – if abnormal noise or pressure fluctuation occurs, first check suction lines for leakage or blockage.

• Regularly check torque on pump and piping connection bolts to prevent loosening from vibration.