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Kracht KF 3-6 Operating Instructions Manual

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D.0024860002
Operating instructions (Translation)
Gear pump KF 3-6
English
17 • 11/03/2025

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Summary of Contents for Kracht KF 3-6

  • Page 1 D.0024860002 Operating instructions (Translation) Gear pump KF 3-6 English 17 • 11/03/2025...

  • Page 2: Table Of Contents

    Table of content Kracht GmbH Table of content 1 General ............................1.1 About the documentation..........................1.2 Manufacturer address ............................ 1.3 Other applicable documents ........................1.4 Symbols................................2 Safety............................2.1 Intended use ..............................2.2 Personal qualification ............................. 2.3 Basic safety instructions ..........................
  • Page 3 Kracht GmbH Table of content 6 Installation ..........................36 6.1 Safety instructions for installation......................36 6.2 Noise reduction ..............................37 6.3 Mechanical installation ..........................38 6.3.1 Preparation............................38 6.3.2 Gear pump with free shaft end ....................38 6.4 Connection lines............................... 40 6.4.1...
  • Page 4 Table of content Kracht GmbH 9.4.18 Replacing the plain bearings....................56 9.4.19 Replacing the shaft seal ......................56 9.4.20 Replacing other seals ........................56 10 Repair ............................57 10.1 Safety instructions for repairs ........................57 10.2 General ................................. 58 10.3 Fault table ................................59...

  • Page 5: General

    1.1 About the documentation These operating instructions describe the installation, operation and maintenance of the follow- ing product: Gear pump KF 3-6 These operating instructions are an integral part of the product and must be kept in the imme- diate vicinity of the product and accessible to the personnel at all time.

  • Page 6: Symbols

    1 | General Kracht GmbH 1.4 Symbols DANGER Identification of an immediate hazard, which can lead to death or severe bodily injury if not avoided. WARNING Identification of a potential medium risk hazard, which can lead to death or severe bodily injury if not avoided.

  • Page 7: Safety

    Kracht GmbH Safety | 2 2 Safety 2.1 Intended use 1. The product has been designed for operation with fluids. Dry operation is not permitted. 2. The product may only be operated when completely filled. 3. The fluid must be compatible with the materials used in the product. Chemical expertise is required for that.

  • Page 8: Basic Safety Instructions

    2 | Safety Kracht GmbH 2.3 Basic safety instructions NOTICE Basic safety instructions Non-compliance can lead to hazards for people and the unit. a) Follow existing regulations for accident prevention and safety at work as well as the internal regulations of the operating company.
  • Page 9 Kracht GmbH Safety | 2 DANGER Rotating parts Risk to life due to entanglement or winding of parts of the body, hair or clothing items. a) Take measures to prevent accidental touching of rotating parts. WARNING Rotating parts Risk of injury caused by ejected parts a) Enclose rotating parts so that in the event of fracture or malfunction, there is no risk caused by ejected parts.

  • Page 10: Device Description

    3 | Device description Kracht GmbH 3 Device description 3.1 Functional principle The pumps of this series are external gear pumps, which operate according to the displacement principle. Suction connection Pressure connection During rotation, two interlocking gears cause a volume increase by opening the tooth spaces on...

  • Page 11: Variants

    Kracht GmbH Device description | 3 3.2 Variants Gear pump End cover Seal Housing Plain bearings Driven shaft Gears O-ring Flange cover Roller bearings 10 O-ring 11 Seal retainer 12 Shaft seal (Types of seals [} 16]) 13 End of drive shaft...
  • Page 12 3 | Device description Kracht GmbH Gear pump with pressure relief valve 1 Pressure relief valve 2 Gear pump 3 Collar nut 4 Cover 5 Adjustment screw Gear pump with Universal valve 1 Universal valve 2 Gear pump 3 Piston...

  • Page 13: Type Key

    Kracht GmbH Device description | 3 3.3 Type key Ordering example 3/100 6 F 1 0 B 6 Z V G D W /197 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
  • Page 14 3 | Device description Kracht GmbH Explanation of type key 8. Flange cover material 2 EN-GJS-400-15 6 EN-GJL-250 4 EN-GJS-400-18-LT 9. Shaft end Cylindrical reinforced shaft end Z Cylindrical shaft end with centring hole DIN 332-2 Cylindrical reinforced shaft end...
  • Page 15 Kracht GmbH Device description | 3 Explanation of type key 20. Seal type Triple rotary shaft seal 0 Without shaft seal Without connection for liquid sup- Triple rotary shaft seal W Rotary shaft seal With connection for liquid supply Double rotary shaft seal...

  • Page 16: Direction Of Rotation And Discharge

    3 | Device description Kracht GmbH 3.4 Direction of rotation and discharge The direction of rotation is indicated by the curved arrow, when looking towards the end of the drive shaft. The pump connections are below the drive shaft. The flow direction is indicated by the straight arrow.
  • Page 17 Kracht GmbH Device description | 3 Double rotary shaft seal Double rotary shaft seal (for vacuum operation) Connecting pipe 8x1 (for fluid buffer) Connecting pipe 8x1 (for fluid buffer) Triple rotary shaft seal Double rotary shaft seal (for vacuum operation / for normal operation)

  • Page 18: Fluid Seal

    3 | Device description Kracht GmbH Mechanical seal Without shaft seal Without shaft seal without roller bearings 3.6 Fluid seal Versions with a fluid seal are used if absolute leak tightness is required at the shaft seal, e.g. when pumping media –...

  • Page 19: Special Numbers

    Kracht GmbH Device description | 3 3.7 Special numbers Special number Description 6-hole mounting flange Tapered shaft end End cover with pipe thread With inserts Customised Second shaft end Adapter For vacuum operation Shaft end bored through End cover with Connection M22x1,5 Special number 79 End cover with G ½...
  • Page 20 3 | Device description Kracht GmbH Special number Description Combination of Special number 122 + 197 Combination of Special number 79 + 197 Combination of Special number 155 + 197 All fastening screws made of stainless steel + Special number 197...

  • Page 21: Special Numbers

    Kracht GmbH Device description | 3 Special number Description For compressor applications Mechanical seal Sliding ring: SiC-Si Counter ring: Resin-impregnated carbon Optimised seal lubrication Plastic plain bearings (non-ferrous metal-free) Mounting position: Shaft end horizontal For compressor applications Special number 445...

  • Page 22: Shaft Ends

    3 | Device description Kracht GmbH 3.9 Shaft ends Size Shaft end Outbord bearing Without 21.5 Z-Shaft KF 3 R-Shaft with M-Shaft Z-Shaft KF 4 R-Shaft with M-Shaft Z-Shaft KF 5 R-Shaft with M-Shaft Z-Shaft KF 6 M-Shaft with 88024860002-17...
  • Page 23 Kracht GmbH Device description | 3 Size with Special num- KF 3 153/172/177/ 21.5 379/415 KF 4 445/446/447/ Mechanical 21.5 seal KF 5 KF 6 153/172/447 88024860002-17...

  • Page 24: Technical Data

    4 | Technical data Kracht GmbH 4 Technical data 4.1 General General information KF 3 SAE 1 1/2" – M10 KF 4 SAE 2“ KF 5/200 SAE 2 1/2" KF 5/250–315 SAE 3“ – M12 KF 6 SAE 4“ KF 3-4 with Universal valve SAE 2“...

  • Page 25: Nominal Sizes

    Kracht GmbH Technical data | 4 General information Materials Material data [} 31] Lubricating fluids without abrasive components (Petrols, solvents, etc. are not permissible) Permissible media For compressor applications : Refrigeration oil (max. 5% gas content), Hydraulic oil; Mineral oil A reduced shaft seal life is possible in the vertical installation position (shaft end at the top).

  • Page 26: Assignment Of Viscosity - Speed

    4 | Technical data Kracht GmbH 4.3 Assignment of viscosity - speed Kinematic viscosity ν [mm²/s] Recommended rpm n [rpm] 2000 1800 1000 1200 2000 3000 6000 10000 15000 20000 Select the speed of rotation so that complete filling of the pump is ensured. This is the case if the pressure on the suction side does not fall below the permissible pressure pe min.

  • Page 27: Allowable Pressures

    Kracht GmbH Technical data | 4 4.4 Allowable pressures 4.4.1 Operating pressure at suction side Seal ma- Seal type Special number Operating pressure terial Suction side Pressure side [bar [bar [bar] e min abs. e max rel. Rotary shaft seal - - - (KF 5/.: 0.5)

  • Page 28: Operating Pressure At Pressure Side

    4 | Technical data Kracht GmbH with Universal valve Nominal Operating pressure Suction side [bar [bar e min abs. e max rel. KF 3/63 KF 3/80 0.64 KF 3/100 KF 3/112 0.65 KF 4/125 0.66 KF 4/150 0.67 KF 4/180 0.68...

  • Page 29: Assignment Of Differential Pressure To Viscosity

    Kracht GmbH Technical data | 4 4.5 Assignment of differential pressure to viscosity Plain bearings ∆p [bar] ν= 1,4 mm²/s ν= 6 mm²/s ν= 12 mm²/s KF 3/. Multi layer fric- KF 4/. tion bearings KF 5/200 (contains lead) KF 5/250...

  • Page 30: Permissible Temperature Range

    4 | Technical data Kracht GmbH 4.6 Permissible temperature range Sealing material Fluid temperature ϑ ϑ ϑ [°C] m min[] m max EPDM FEP with FKM-core FFKM / FEP with FKM-core HNBR PTFE / FEP with FKM-core FKM ( Low temperature) Sealing material Ambient temperature ϑ...

  • Page 31: Material Data

    Kracht GmbH Technical data | 4 4.7 Material data Seal type Materials Shaft seal O-ring / Gas- Housing / Gears Plain bearings Flange cover / End cover / Valve housing NBR, Rotary shaft C4400 seal FKM, - - - C4400...

  • Page 32: Compressor Application

    4 | Technical data Kracht GmbH 4.7.1 Compressor application Refrigerant R717 CR / CR / CR / CR / Ammonia (NH3) HNBR HNBR HNBR HNBR HNBR R290 Propane HNBR HNBR (C3H8) R1270 Propylene HNBR HNBR (C3H6) R744 Carbon diox- HNBR...

  • Page 33: Dimensions

    Kracht GmbH Technical data | 4 4.9 Dimensions The dimensions of the product are given in the technical data sheets. 88024860002-17...

  • Page 34: Transport And Storage

    5 | Transport and storage Kracht GmbH 5 Transport and storage 5.1 General a) After receiving the delivery, check the product for transport damage. b) If transport damage is found, the manufacturer and the transport company must be notified immediately. The product must then be replaced or repaired.

  • Page 35: Storage Conditions

    Kracht GmbH Transport and storage | 5 Products with EPDM seals are not mineral oil resistant and their function is not tested. The in- ternal parts are not preserved. If the product is not put into operation immediately, all surfaces exposed to corrosion must be protected by suitable preservation measures.

  • Page 36: Installation

    6 | Installation Kracht GmbH 6 Installation 6.1 Safety instructions for installation DANGER Hazardous fluids Danger to life when handling hazardous fluids a) Comply with the safety data sheets and regulations on handling the hazardous fluids. b) Collect and dispose of hazardous fluids so that no hazard is created for persons or the en- vironment.

  • Page 37: Noise Reduction

    Kracht GmbH Installation | 6 WARNING Failure of pressure bearing parts due to overload Risk of injury from flying parts. Risk of injury due to splashing fluids. a) Before carrying out any work, depressurise the product and all connection pipes.

  • Page 38: Mechanical Installation

    6 | Installation Kracht GmbH 6.3 Mechanical installation 6.3.1 Preparation a) Check the product for transport damage and contamination. b) Check the product for smooth and easy movement. c) Remove any preservative present. d) Clean all lines. ð Only use cleaning agents that are compatible with the materials used.
  • Page 39 Kracht GmbH Installation | 6 CAUTION Hot surfaces Burns of the skin on contact. a) Wear protective gloves at temperatures ≥48°C. Tightening torques [Nm] Thread size Counter-thread Aluminium Counter-thread Cast iron / Steel Screws/Nuts with min. strength class 8.8/8 NOTICE a) Comply with the allowable displacement values of the coupling.

  • Page 40: Connection Lines

    6 | Installation Kracht GmbH 6.4 Connection lines 6.4.1 General WARNING Failure of pressure bearing parts due to overload Risk of injury from flying parts. Risk of injury due to splashing fluids. a) Use only connections and lines approved for the expected pressure range.
  • Page 41 Kracht GmbH Installation | 6 Suction line at vacuum operation If medium is to be drawn from a tank under va- cuum, the pump must be positioned approx. 1 m below the tank. The suction line must be laid straight and without any resistances.

  • Page 42: Pressure Pipe

    6 | Installation Kracht GmbH 6.4.3 Pressure pipe When designing the lines, bear in mind the following points: – Choose the nominal size of the pressure line so that the maximum permissible pressures are not exceeded. – If necessary, provide a venting nozzle to prevent suction problems.

  • Page 43: Gear Pump Without Noise Optimisation

    Kracht GmbH Installation | 6 6.5.1 Gear pump without noise optimisation Suction connection Fastening screws Pressure connection Leak oil hole Adjustment screw To change the direction of rotation of the gear pump, turn the end cover or the pressure relief valve 180°.

  • Page 44: Gear Pump With Noise Optimisation

    6 | Installation Kracht GmbH 6.5.2 Gear pump with noise optimisation Suction connection Fastening screws Pressure connection Leak oil hole Adjustment screw To change the direction of rotation of the gear pump, turn the end cover or the pressure relief valve 180°.

  • Page 45: Commissioning

    Kracht GmbH Commissioning | 7 7 Commissioning 7.1 Safety instructions for start-up DANGER Hazardous fluids Danger to life when handling hazardous fluids a) Comply with the safety data sheets and regulations on handling the hazardous fluids. b) Collect and dispose of hazardous fluids so that no hazard is created for persons or the en- vironment.

  • Page 46: Filling The Quench Chamber

    7 | Commissioning Kracht GmbH 7.3 Filling the quench chamber Quench chamber Container for quench-liquid a) For versions with fluid seal, fill the quench chamber with a suitable seal fluid. ð Fill from the tank provided. ð Fill fluid until the quench chamber is completely full and the tank is half full.

  • Page 47: Pressure Relief Valve

    Kracht GmbH Commissioning | 7 response pressure lower Cover response pressure higher Collar nut Adjustment screw a) Remove cover. b) Loosen the hexagon nut. c) Use the adjusting screw to set the set pressure. d) Secure the adjusting screw with a hexagon nut.

  • Page 48: Additional Commissioning

    7 | Commissioning Kracht GmbH 7.5 Additional commissioning a) Open existing shut-off elements in front of and behind the product. b) Set pressure relief valves installed in the system to the lowest opening pressure. c) Start the product without pressure load or with low pressure (jog mode).

  • Page 49: Removal

    Kracht GmbH Removal | 8 8 Removal 8.1 Safety instructions for disassembly DANGER Hazardous fluids Danger to life when handling hazardous fluids a) Comply with the safety data sheets and regulations on handling the hazardous fluids. b) Collect and dispose of hazardous fluids so that no hazard is created for persons or the en- vironment.

  • Page 50: Dismantling

    8 | Removal Kracht GmbH ATTENTION Blocking of the product due to curing media Curing media can mechanically block the product and make it unusable. a) Clean the product immediately after operation with curing media. 8.2 Dismantling a) Depressurise and de-energise the system.

  • Page 51: Maintenance

    Kracht GmbH Maintenance | 9 9 Maintenance 9.1 Safety instructions for maintenance DANGER Hazardous fluids Danger to life when handling hazardous fluids a) Comply with the safety data sheets and regulations on handling the hazardous fluids. b) Collect and dispose of hazardous fluids so that no hazard is created for persons or the en- vironment.

  • Page 52: Maintenance Work

    9 | Maintenance Kracht GmbH 9.2 Maintenance work Checking and documentation of the operating data Regular checking and documentation of all operating data helps to detect faults at an early stage. – Perform the maintenance work according to specifications. – Replace defective or worn components.

  • Page 53: Maintenance Table

    Kracht GmbH Maintenance | 9 9.4 Maintenance table 9.4.1 Maintenance table Additional in- formation 9.4.2 Check the operating pressure 9.4.3 Check the media temperature 9.4.4 Check the device temperature 9.4.5 Check the function of the add-on valve 9.4.6 Check the equipotential bonding 9.4.7...

  • Page 54: Check The Operating Pressure

    9 | Maintenance Kracht GmbH 9.4.2 Check the operating pressure The operating pressure is indicated by the pressure gauges. – If there is no operating pressure, check the individual components of the product. – Comply with the product-specific data sheets/operating instructions.

  • Page 55: Visual Check Of Seal Fluid Level

    Kracht GmbH Maintenance | 9 9.4.11 Visual check of seal fluid level Pay attention to the level of the seal fluid. If necessary, top up the seal fluid. If there is no automatic monitoring, the filling level must be checked at least before each shift begins.

  • Page 56: Visual Check Of The Condition Of The Outboard Bearing

    9 | Maintenance Kracht GmbH 9.4.16 Visual check of the condition of the outboard bearing The outboard bearing is a wearing part. The life of the bearing primarily depends on the operating conditions. The bearing should therefore be checked for damage after 4000 h at the latest. In the event of unacceptable wear, the bearing must be replaced.

  • Page 57: Repair

    Kracht GmbH Repair | 10 10 Repair 10.1 Safety instructions for repairs DANGER Hazardous fluids Danger to life when handling hazardous fluids a) Comply with the safety data sheets and regulations on handling the hazardous fluids. b) Collect and dispose of hazardous fluids so that no hazard is created for persons or the en- vironment.

  • Page 58: General

    10 | Repair Kracht GmbH 10.2 General Corrective maintenance includes: 1. Troubleshooting Finding damage, determining and localising the cause of the damage. 2. Damage repair Removing the primary causes and replacing or repairing defective components. Repairs are generally carried out by the manufacturer.

  • Page 59: Fault Table

    Kracht GmbH Repair | 10 10.3 Fault table Fault Potential causes Possible measures Increased noise Excessive negative pressure Check suction line design (not complete filling of the Use noise-optimised pump pump) Suction line clogged Clean the suction line Clean suction filter or use a lar-...
  • Page 60 10 | Repair Kracht GmbH Pump does not suck Reduce the start-up pressure The air in the suction line can- Vent the pressure line not be compressed in the pres- Increase volume of the pres- sure line sure line Check the pump design...
  • Page 61 Kracht GmbH Repair | 10 Impermissible pump heating Constant triggering of pressure Increase valve opening pres- relief valve (if existing) sure Pressure too high in associ- ation with a media viscosity Check the system design that is too low Speed too fast in connection...
  • Page 62 10 | Repair Kracht GmbH Correct the alignment of the coupling and secure the coup- Alignment error ling halves Premature spider wear Replace spider Check material compatibility Spider failure due to chemical corrosion Replace spider Motor protection switch tripped Driving power too low...

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