Retrofitted control heads extend life of 200 process valves

The food and beverage industry uses process control valves extensively to manage the flow of liquids and gases throughout the manufacturing process. As such, their reliability is essential to the continued operation of the food manufacturing process: keeping sufficient spare parts available is therefore an important task.

However, as equipment ages, the original equipment manufacturer (OEM) may no longer support the product. At this point, maintenance managers can be left with just their own stock of spare parts, which will, inevitably, run out at some point.

In this case, the food manufacturer took the opportunity to investigate the alternatives, starting with replacing the control valves completely. With over 200 process control valves affected, replacement would be a substantial investment and the payback period would have been longer than desired.

At the same time, Brkert, as an existing supplier to the company, was invited to offer a solution. Craig Kerr, Sales Manager at Brkert, explains: "We were provided with a spare control valve from the production line and asked to deliver a proposal that would resolve the issue of ageing controls, while retaining the value in the valve body."

As a major manufacturer of process control valves, Burkert could have offered a complete replacement valve, but having assessed the condition of the valve body decided that just the control head needed attention. The obsolete pneumatic actuator could be replaced with Brkert's Type 8691 control head with the simple addition of an adapting bracket to attach it to the legacy valves.

Plug & Play

Craig continues: "The manufacturing process operates a decentralised control system using ASI, with the valves either open or closed. Brkert's suggested solution would provide a simple, plug-and-play control head that would easily attach to the control valve body."

In all, it would take less than an hour to replace each control head. This includes assigning an address for the PLC and using the tuning function where the operator presses the buttons to open and close the valve. The integrated valve position sensor registers these points and stores them to ensure reliable valve operation.

The Type 8691 is well suited to the food and beverage industry; being constructed from stainless steel, with excellent ingress protection ratings, it is easy to clean and has excellent chemical resistance properties. In addition, it is equipped with bright, coloured LED status indicators that show the position of the valve at a glance.

Craig concludes: "The customer had the first unit on trial for a short period before ordering a further one hundred units. These were all installed and commissioned by the customer and one year on, they are all continuing to function reliably. This solution has been very cost-effective, saving thousands in process hardware and replacement costs by allowing the customer to retain the original valves and minimise any potential downtime from the upgrade."

Learn more at www.burkert.co.uk.