Deep technical knowledge and fast support

At the UTO waste treatment plant in Central Valais, viscous lime-milk-water mixture is injected into water basins for recovery. For correct dosing, valves suitable for this medium are needed.

The Waste treatment plant UTO recycles around 70,500 tonnes of waste per year from 31 municipalities in central Valais. This includes the waste of almost 170,000 inhabitants. Heat is released during waste incineration. This heat is used to generate electrical and thermal energy. The waste treatment plant is located in Uvrier in the municipality of Sion in the heart of Valais.

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Initial situation/Challenges for the customer

The UTO waste treatment plant in Central Valais consists of various departments. In the water treatment department, the products used are very aggressive.

Milk of lime is injected into large water basins to recover the acidic water after flue gas cleaning. The aim is to make the water clear and alkaline (7 PH) so that it can then be discharged into the Rhône.

Milk of lime is a powder that is mixed with water before being injected into the basins to be treated. This lime milk-water mixture is very viscous and clogs the pipes and valves very quickly. For correct dosing, valves suitable for this medium are needed in several basins.

Therefore, Mr Julien Surchat of the UTO waste treatment plant in Central Valais needs a competent partner for industrial automation.


For the very viscous lime-milk-water mixture, Mr Julien Surchat uses two pipes in parallel to be able to switch quickly in case of a blockage. There is a manual valve on each pipe, followed by a control valve and a safety valve.

In personal discussions and joint exchanges, TRI-MATIC familiarised itself with the process and the conditions of the plant. TRI-MATIC's goal was to offer valves adapted to the medium with quick connections for assembly and disassembly.

The valves must be easy to dismantle and reassemble in the event of blockages caused by the very viscous lime-milk-water mixture. An identical diaphragm for each valve enables Mr Surchat to carry out maintenance easily and quickly. The hardness and durability of the valves is also an important factor because of the very aggressive products. Due to these circumstances, TRI-MATIC has opted for diaphragm valves with clamp connections.


Thanks to the valves adapted to the viscous medium, the waste treatment plant runs smoothly and is easy to maintain. Thus, the operating costs of the plant are lower.

For Mr Julien Surchat it is clear: "The broad and deep technical knowledge, the fast support and the high flexibility are what I really appreciate about TRI-MATIC. Also very valuable to me is the personal advice that fits our needs and the relationship that has developed over the years."