HOW TO (AND WHY): CONDITION MONITORING AT THE LIQUIDYNE®

By Rakesh Soekhoe, Ashley van der Vlies

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 (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.

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 this link!

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

 

(Persbericht Lagersmit, januari 2016)