Lime Slurry used in Water Works

User: Crown Hill Waterworks, SouthWest Water, UK

Hose full of lime milk deposits

South West Water is supplying the southwest of England with water. The drinking water is treated before it is brought to the customer. In most cases one process step is done to stabilize the pH-value of the water. It needs to be at least 6,5 pH for drinking water.

Often lime slurry is used for this process step. Lime slurry is “liquid” lime – whitewash. Therefore huge amounts of limescale are transported in the water and settle in pipes and machines. Often hoses are used rather than iron pipes as they are easier to exchange when blocked.

The first picture shows the inside of one of these hoses after a few days of operation. It was taken right before the Merus Ring was installed. The hose is180 m long and both ends look the same. Therefore we assume, the deposits settled over the entire length. We installed one Merus Ring right behind the shut-off valve at the beginning of the hose.



Limeslurry causes several technical problems for the water suppliers. Not only hoses, pipes and water tanks are heavily affected by limescale. Especially the pumps supplying the water tanks with the lime slurry are often blocked by limescale. This leads to frequent downtimes. There needs to be a service team available 24/7.

Results with a Merus Ring

After the installation of the Merus Ring no limescale could settle in the hose anymore. As you can see in the second picNo scale in the hose after 4 weeks Merus Ringsture the hose treated with the Merus Ring is clean. Limescale is visible only on the outside of the connecting piece.

The pumps which required frequent servicing weren’t blocked anymore and far less maintenance and emergency repair was necessary.

Thus the investment for the Merus Ring payed off after some months. Since this first test we installed some hundreds of Merus Rings where lime slurry is used. Not only at water suppliers but also in the mining industry.


We use cookies to ensure that we give you the best experience on our website and to improve the relevance of our communications with you. If you continue without changing your settings, we’ll assume that you are happy to receive all cookies on the merusonline website. However, if you would like to, you can change your cookie settings or find detailed information about how cookies are used on this website by going to 'Data protection'.