VETUS ZWBH Propeller Shaft Seal Installation and Maintenance Manual

1. Safety

Warning Indications

DANGER: Indicates that great potential danger exists that can lead to serious injury or death.

WARNING: Indicates that a potential danger that can lead to injury exists.

NOTE: Emphasises important procedures, circumstances etc.

General rules and laws concerning safety and accident prevention must always be observed.

WARNING: This product should only be installed and maintained by qualified personnel who have read and understood the instructions and precautions in this manual. Failure to follow the instructions in this manual may result in serious injury or property damage. The manufacturer shall not be liable for any damages resulting from improper installation or maintenance by unqualified personnel.

2. Introduction

This manual contains guidelines for the correct installation and maintenance of the VETUS ZWBH shaft seal. Follow the instructions carefully to ensure proper operation and a long service life of the system.

3. Installation Preparation

WARNING: To ensure proper sealing, the propeller shaft must have a maximum diameter tolerance of +0.0 mm / -0.16 mm and must be centrally aligned in the stern tube.

WARNING: Align the propeller shaft with the ship's engine before installing the shaft seal!

WARNING: The propeller shaft speed must not exceed the values listed below:

3.1 Inspection of Stern Tube and Propeller Shaft

• Remove burrs, grease, and dirt from the exposed length of the stern tube (Dimension A).
• Ensure the exposed length of the stern tube corresponds to Dimension A.
• Remove all scratches, burrs, and contamination from the shaft, especially at the location of the shaft seal (Dimension B).
• The free length between the stern tube and the flexible coupling must match Dimension B.
• Ensure the shaft is inserted into the stern tube.

4. Lubrication and Cooling

4.1 Raw Water Cooling

The shaft seal, the external bearing (on the propeller side), and any intermediate bearing are cooled and lubricated by the supply of raw water.

WARNING: Insufficient water supply during shaft rotation can lead to overheating and damage.

4.2 Water Supply

• Option 1: Branch from the engine's raw water cooling system. (See Diagram 2). When using a vented loop: Place the branch between the raw water pump and the vented loop, not between the vented loop and the injection point. (See Diagram 3).
• Option 2: Scoop-type intake with shut-off valve (minimum G 3/8 for shaft diameters of 25, 30, 35, or 40 mm), installed with inlet slots facing forward, without disturbing the propeller wash. (See Diagram 4).

The shaft seal may be installed either below or above the waterline. If installed above the waterline, connect the water supply as shown in Diagram 2.

4.3 Additional Grease

Apply the supplied grease between the two sealing lips of the seal. (See Diagram 5).

5. Final Assembly

(See Diagrams 6 through 10).

1. Tape over keyway: Apply tape ('A') over the keyway to prevent damage to sealing lips.

   NOTE: Damage to the sealing lips will cause leakage!

2. Greasing: Grease the shaft at the shaft seal position. Also grease the sealing lips. Use only the supplied grease.
3. Installing the shaft seal:
   • Place the sleeve with two hose clamps over the shaft and the stern tube.
   • The internal collar must rest against the end of the stern tube.
   • Tighten the hose clamps to a torque of 4 to 5 Nm.
4. Filling the grease chamber:
   • Remove the Allen screw.
   • Fill the grease chamber to approximately 50% (± 1 cm³) with the supplied grease.
   • Reinstall the Allen screw.
5. Connecting the water supply:
   • Connect the hose pillar (the water inlet) using a hose (Ø 10 mm internal) to the water supply.
   • Secure the hose with two stainless steel hose clamps.

6. Initial Commissioning (after launching)

Vent the system after launching by disconnecting the water supply hose on top of the shaft seal until water flows from the hose pillar. Reconnect the water hose and check the shaft seal and hose connections for leaks.

7. Operation

• Always open the shut-off valve (if using a scoop-type intake) before departure.
• During operation, check the shaft seal for leaks and monitor temperature. A high temperature indicates insufficient water for lubrication and cooling.

WARNING: High temperature is a sign of inadequate water supply.

8. Periodic Maintenance

Perform the following tasks after every 200 operating hours or at least once a year (preferably when the boat is out of the water):

1. Loosen the hose clamps.
2. Slide the seal toward the coupling.
3. Clean the running surface of the sealing lips on the shaft (remove grease, dirt, and deposits).
4. Apply new grease to the running surface and sealing lips.
5. Reinstall the seal onto the stern tube.
6. Retighten the hose clamps (torque 4 to 5 Nm).
7. Check again for leaks after relaunching.

9. Important Tips

• Use only the supplied grease.
• Avoid damage to the sealing lips during installation.
• Regularly check operation and temperature during use.
• Follow the maintenance schedule strictly for optimal performance.

Diagram Descriptions

Diagram 1: Shows the principal dimensions of the shaft seal. It illustrates measurements D (outer diameter), d (inner diameter), H (height), and L (length) for various shaft sizes (Ø 25, Ø 30, Ø 35, Ø 40 mm).

Diagram 2: Illustrates Option 1 for water supply, showing a connection branching from the engine's raw water cooling system to the shaft seal.

Diagram 3: Illustrates the placement of the water supply branch when using a vented loop, showing the connection point between the raw water pump and the vented loop.

Diagram 4: Depicts Option 2 for water supply, featuring a scoop-type intake with a shut-off valve, designed to be installed facing forward without disturbing propeller wash.

Diagram 5: Shows the application of grease between the two sealing lips of the shaft seal.

Diagrams 6-10: Illustrate the final assembly steps:

• 6. Applying tape ('A') over the shaft keyway to prevent damage to sealing lips.
• 7. Greasing the shaft at the shaft seal position and the sealing lips with supplied grease.
• 8. Placing the shaft seal sleeve over the shaft and stern tube, ensuring the internal collar aligns with the stern tube end.
• 9. Filling the grease chamber with approximately 50% (± 1 cm³) of the supplied grease after removing the Allen screw.
• 10. Connecting the water supply hose (Ø 10 mm internal) to the hose pillar and securing it with stainless steel hose clamps.