Condition Monitoring at the Liquidyne®

Eric De Paauw

The water lubricated Liquidyne® seal was initially developed for dredge pumps running in harsh environments. Now you can prevent unexpected maintenance by measuring the condition of the seal at any time. We call this Condition Monitoring and this very aspect is what makes the Liquidyne unique. To date, the Liquidyne pump seals are successfully applied to dredge pumps, (cooling) water pumps, booster pumps, slurry pumps and many other applications. How does it work? We will briefly explain below.

How does the Liquidyne work?

Before we can make it clear how the condition of this seal is determined, it is useful to understand how the seal works in general. The grooved bush of a Liquidyne contains helical grooves and is coated with a hard metal wear layer. Thanks to the pressure reducing module, the Liquidyne can handle relatively high operating pressures. The lip seal(s) of the pressure reducing module(s) ‘run’ over the grooves. This play, coupled with the rotary movement of the bush, creates a flow of water between the lip seals and the grooved bush. The lip seal(s) running over the created water flow is very similar to aquaplaning. It lubricates the lip seal with water, cools the module and minimises friction. The water is transported from the pump side to the drain side of the seal and runs out of the drain.

How does condition monitoring work?

Over time, the grooves on the bush wear down. As a result, less water is transported over the bush and the water flow at the drain side decreases. If this drain flow is at 20% of the initial flow, maintenance is required. Recording the drain flow from the moment the seal was taken into use allows for maintenance to be scheduled more efficiently and the maintenance interval to be maximised. This prevents sudden failure and damage to the pump. Furthermore, the costs are reduced to a minimum because unnecessary maintenance is prevented.


How should you measure?

In collaboration with Royal IHC, we made a video about monitoring the condition of a Liquidyne. How does it work? And what should be measured? Find out in the video below!


What should you take notice of?

Our specialists are often asked exactly what one should take notice of when checking the condition of the seal. Most important is to measure the following within fixed time intervals:


  • Water inflow and outflow (litres/hour)
  • Temperature difference between inflowing and outflowing water


3 reasons for condition monitoring

  • Predictable service life = no risk of sudden failure of the seal + realising and maintaining a carefree production output
  • Extending the product life = no (early) preventive maintenance and unnecessary costs
  • Sealing


Contact us for more information.

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