Innovations (5) – The Pump Gear Bulkhead Seal

The Pump Gear Bulkhead Seal is designed for safeguarding the CSD’s pump gear machine room. This sealing solution is a proven, highly reliable sealing solution for 24/7 dredging operations. It is designed to keep you going and takes the next step in both performance and reliability. Keep reading to find out more!


Summarised: the benefits!

  • Proven seal technology that protects the pump gear machine room
  • Zero-emissions to the water environment
  • Pressure compensation at varying depths
  • Operates at greater depths (>15 m below the water line)
  • Flexibility and (bearing) support to manage 5 mm of radial displacement
  • Minimal wear on lip seals and the support bearing
  • Condition Monitoring for planned maintenance and minimal risk of sudden failure
  • Continued operation if Lube Oil Unit needs to be maintained

The Pump Gear Bulkhead Seal

Conventional seals are not able to perform under harsh dredging conditions that Cutter Suction Dredgers (CSDs) encounter every day during their activities. For this sole purpose, Lagersmit has developed a highly reliable pump gear bulkhead sealing solution, which can handle large bulkhead and shaft deformations and can operate in abrasive environments at draughts of 16 m.

Picture 1: Pump Gear Bulkhead Seal

The Pump Gear Bulkhead sealing system consists of a floating seal with a protection cover and a lubrication system with and Supreme Ventus® system, which are equipped with all necessary sensors for controlling and monitoring the seals. The Pump Gear Bulkhead seal is installed on the underwater pump shaft and is mounted to the bulkhead of the underwater pump gear machine room.

The “floating” seal will follow the radial shaft movement by means of a segment with an integrated white metal slide bearing. This way conditions for proper static alignment and run-out are met automatically.

All oil connections are made on the inboard side of the seal; no extra passages through the bulkhead are needed.

The Supreme Ventus system

The Supreme Ventus system decreases the pressure differences over the lip seals, meaning the heat generated by friction will be less, to lengthen the lifetime of the Supreme lip seals.
An additional benefit of the Ventus system is the ability to monitor the lip seal wear by draining any leakage into a drain tank. The leakage rate illustrates the amount of wear on your lip seals.

The Ventus system has been used for seals in propulsion systems for over a decade now and it is believed by many ship owners and propulsion manufacturers to be a valuable asset to your sealing system.

The lubrication system

The lubrication system comprises two lube oil systems. The lube oil system circulates the oil and controls pressure, flow and temperature in order to build up an appropriate lubrication film for the white metal slide bearing.

The lubrication system has a redundant pump set and filter, making it possible to perform maintenance while the dredging operation continues.

Lagersmit is not only responsible for the development and production of the sealing system, but also performs the installation of the seal and commissions the complete sealing system and system controls.

Want to know how we keep you going?

More information and contact

If you  want more information about if and how this seal match your applications, contact our seal expert Jan Willem!

About the author: Pepijn Swarte

Pepijn studied industrial design engineering at the Delft University of Technology and at The Hague University of Applied Sciences. He has been working for Lagersmit since 2013 and as Product Manager he is responsible for the research and development activities of the Supreme seals.