How to (and why): Condition Monitoring at the Liquidyne®

By Rakesh Soekhoe, Ashley van der Vlies

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?

Figure 1: Working of the Liquidyne

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 (see also Figure 1).

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.

Figure 2: Conditioning Monitoring

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 by clicking on the link 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

Why? These are the reasons for Condition Monitoring!

How does the Liquidyne give you peace of mind?

  • 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

More information

Would you like more information about our Liquidyne? Do not hesitate to contact me!

More information about  the Liquidyne

Time for maintenance?

About the authors

Rakesh Soekhoe

Rakesh graduated from Delft University of Technology with a Master’s degree in Integrated Product Design with a focus on sustainability. He is one of Lagersmit’s product specialists and has a full focus on Liquidyne pump shaft seals. In this role he is responsible for the technical expertise concerning Liquidyne and in particular, research and development activities of the Liquidyne seals.

Ashley van der Vlies

Ashley studied Communications at the Inholland University of Applied Sciences. After graduating in 2006, she has been working in various branches. She started at Lagersmit as an Online Marketeer early 2015. She is mainly responsible for generating leads through the online channels (website, social media, online advertising) and also for providing the content for these channels.