AVK Butterfly Valves to the rescue in South Africa

EVS Butterfly valve manufactured by Woutel Witzel rescued a water plant in South Africa, solving critical situation of unwanted downtime due to a continuously failing butterfly valve.

A prominent mining house was faced with a persistent problem of valve failures at its crucial water reclamation plant and sought the expertise of AVK Southern Africa through one of the valve manufacturing company’s local distributors, Maduba Mining Supplies, looking for a long-lasting solution.

Built in 2016, to process used mine water, the water reclamation plant was constantly plagued by problematic butterfly valves that kept failing and could barely last six months. As explained by the customer, the reason being the butterfly valves were twisting, and would eventually break off due to scale build-up inside the valve. Therefore, the valve liners protruded out, preventing the valves from closing properly, which in turn caused the actuator to trip over torque. Therefore, the company had to appoint a dedicated person on standby only to get the system back online whenever the actuator tripped.

Putting our valves to the test

After visiting the site to investigate, AVK Southern Africa’s Pieter Swanepoel recommended a Wouter Witzel EVS valve for testing. Having put the valve through its paces for a month, the plant maintenance foreman called Swanepoel to report that the Wouter Witzel EVS had failed, stating that the disc had broken free from the shaft and was “spinning” in the pipeline. Based on his experience with the product, Swanepoel was incredulous about the claimed EVS failure and insisted to be on site when they removed the valve from the line. Once the valve was removed, it was taken to the test bench, where the foreman opened and closed it, only to discover that it was functioning properly. Initially convinced that the valve had failed, the plant foreman was astounded to become aware that the valve did not trip even once during the entire testing period rather it even ran at a lower torque output compared to all the other valves on site. Central to this capability is the fact that the EV valve range (including the EVS) is equipped with a vulcanized liner.

The vulcanization process used to bond the rubber onto the body of the valve is done by means of high temperature and high pressure, eliminating any space between the body and the liner where corrosion or erosion can take place which keeps the torque low and constant over the lifetime of the valve. Hence the vulcanized layer stays in place and gives a drop-tight seal every time.

Immediate improvements

Since its installation some two years ago, the test valve has completed a whopping 200,000 cycles, and counting,the valve opens and closes approximately once every five minutes. Not only has the valve lasted four times longer than the previously specified valve, but it also uses a smaller actuator to open and close, not only reducing running costs also provided a lasting solution for the customer.

Demonstrating undoubtedly Wouter Witzel EV range has an impeccable track record and has continuously proven itself, not only in outlasting its competition, but offering significantly lower cost of ownership. Having experienced these benefits first-hand, the mining house is now converting the whole plant for Wouter Witzel butterfly valves.