Liquidyne® pump shaft seals

Released in 1983, the Liquidyne pump shaft seal was initially intended for heavy-duty dredge pumps and is the next step for gland packing and the alternative of a mechanical seal. Thanks to its robust design, the seal can handle above-average axial and radial play. It is suitable for pumps that have to deal with severe shocks and vibrations, incorrect alignment, and abrasive media. The Liquidyne increases the pump’s lifetime and leads to a longer mean time between maintenance (MTBM) thanks to its robustness. Condition monitoring adds predictability and secures your operation.

Liquidyne vs gland packing

Summarised top advantages:

  • Condition monitoring ensures you can plan maintenance efficiently, optimise MTBM, reduce costs, and minimise the risk of sudden pump failure
  • Energy savings due to less friction and minimised heat development
  • Safe workplace – the floor is kept dry, and no adjustments are required during operation
  • Easy to maintain – no other tasks required besides condition monitoring

Liquidyne vs mechanical seal

Summarised top advantages:

  • Predictable lifetime: condition monitoring minimises the risk of sudden pump failure
  • Optimised cost of ownership thanks to the possibility of ordering spare parts, energy savings, and easy maintenance
  • The Liquidyne has a robust seal design, making it virtually non-sensitive for abrasive media

How the Liquidyne works in a nutshell

The (water) lubricated lip seals run over a partially grooved bush placed over the pump shaft. The helical shape of the grooves and peripheral velocity of the bush create water flow between the grooves and the lip seal.

Predictable lifetime

One of the main benefits of the Liquidyne is that the condition monitoring function is not just to simply monitor the condition of the seal, but it also creates a predictable lifetime. How? Over time, the grooves on the bush gradually wear down. Less water is transported over the bush and the amount of water leaving the drain decreases. When the drain flow is at 20% of the initial flow, maintenance needs to be planned.

By keeping track of this drain flow you can plan maintenance more efficiently, minimising the risk sudden pump failure, optimise mean time between maintenance and reduce costs.

Dredging brochure

Industrial seals

Industrial brochure

New Liquidyne seal

The grooved bush after 10 years, still looking great.

“We installed the first Liquidyne 10 years ago as replacement for gland packing on our cooling water pump. A very simple and proven reliable design, that we have applied on many cooling water pumps!” – Sabic

The seal matching your application

There are five general Liquidyne designs.

Liquidyne 2-Stage
Does the pumpmedium contain little or small abrasive particles?

The Liquidyne 2-Stage is designed for such applications >

Liquidyne 3-stage (WA)
Does the pumps contain big abrasive particles? Is the pump a dredge, sludge or slurry pump?

The Liquidyne 3-Stage (WA) is the designed for these applications >

Liquidyne 3-Stage Vacuum
Does the pump utilize a vacuum to to keep the water chamber filled or does the water chamber start-up dry?

The Liquidyne 3-Stage Vacuum is built for this >

Liquidyne LDS
Does the pump’s stuffing box pressure reach below atmospheric level? Or does the gland run dry when starting up?

The Liquidyne LDS is developed for such applications >

Liquidyne Special Execution
Does the pump has another (special) application?

The Liquidyne Special Execution is a customized solution >


Liquidyne pump shaft seals adding quality and reliability to your operation and has already been successfully installed at around 10.000 pumps. Lagersmit currently delivers Peace of Mind to a vast network of pump manufacturers, dredging, (petro)chemical and energy companies. Jan de Nul, Boskalis, Shell, Nouryon Industrial Chemicals (Formerly AkzoNobel), Stork and Sabic use the Liquidyne to their full satisfaction.

“Thanks to the robustness of the Liquidyne seal, we hardly need to contact Lagersmit. However, if we do need to call them, we can rely on dedicated and solution-oriented people that will help us to take the right action. This works brilliantly.”

Sabicvisit website

“We value the Liquidyne seal for it’s reliability, which helps us to maximise the availability of our equipment.”

Jan de Nulvisit website

“Regarding choosing the best seal for our application, Lagersmit supported us very well.”

Shellvisit shell

“Why I like to work with Lagersmit? Because of the good products and excellent service delivery. In addition, for years I can count on a market rate so that your costs remain under control. With other maritime service providers I sometimes had surprises in that area.”


More information

Eric de Paauw

Eric de Paauw – Account Manager

Account manager

Jan-Willem Bongers – Sales Manager