June 2021

Process valve island helps improve predictive maintenance Maintenance Matters Problem Solver 24 | Plant & Works Engineering www.pwemag.co.uk June 2021 A pneumatic valve island for process automation now includes Switching Time Monitoring to ensure improved predictive maintenance, and long- term dosing accuracy. The new functionality on board Bürkert’s Type 8652 AirLINE pneumatic valve island monitors process valve opening and closing times via feedback to provide accurate and consistent batch quality. Switching Time Monitoring also provides an early alert for potential valve maintenance requirements to avoid unscheduled downtime. Mechanical wear of process valves means that designated valve opening and closing speeds can change over time. Worn process valve seals can increase opening rates and the build-up of residue or debris can slow down valve opening or closing speeds. Changes to valve opening times can lead to underdosing or overdosing, problems that can be difficult to detect as they commonly occur gradually. Bürkert’s Type 8652 AirLINE valve island now features the new Switching Time Monitoring feature that prevents inaccurate dosing by recording and reporting process valve opening and closing times. If switching times deviate from their setpoints, the process valves can be inspected and repaired or replaced to maintain accuracy. A tolerance in switching times can be programmed and a pre-warning alarm is able to notify when the set tolerance is exceeded. For general purpose process applications, where high accuracy isn’t required or closely monitored, the Switching Time Monitoring feature also ensures reliable performance by enabling predictive maintenance. Process valve wear or obstructions identified by the switching time report can now be resolved at pre- determined process shutdowns, avoiding mechanical failure and unplanned downtime. Diagnostic reports are presented in clear text or symbols via the Type 8652’s LCD display. Real time data can also be viewed via Bürkert’s easy to use Communicator PC tool or accessed from any web browser, with remote diagnostics and management speeding up any required maintenance responses. The Type 8652 AirLINE valve island can operate with valves that actuate liquid, gas or fluidic solids and can integrate with a wide variety of control systems, communicating over PROFIBUS DP, all common Ethernet protocols as well as CC-Link and CANopen. The new Switching Time Monitoring function joins other recent updates for the Type 8652 pneumatic valve island including explosion protection to ATEX / IECEx Zone 2 and the External Valve Shutdown (EVS) feature. EVS enables individual valves or complete island modules to be shut off while maintaining network communications to send status data to the PLC. A wastewater pumping system at a large shopping centre in Bristol was causing a headache for facility managers, as it was suffering multiple breakdowns. Designed to pump wastewater from a 1000 L basement tank over a 10m head and along to the main drains, two pumps kick in once a certain level is reached, emptying the tank. However, the 20-year-old system was showing its age. The tank itself was leaking, causing the seepage of wastewater into the basement area. This required clean up, which was jeopardising the reopening of shops post-lockdown. Paul Pearce, sales director at Rotamec, quickly found himself involved in a project to replace the system: “A contractor approached us regarding overhauling the wastewater pumping system at the shopping centre, with facility managers indicating that they would prefer the work to be completed ready for reopening after lockdown. We quickly arrived on-site to assess the system.” After a thorough inspection, it was clear that the whole system required replacement with a more efficient and reliable solution. The ageing tank, pumps, valves, electrics and control system would all require replacing. “We offer a turnkey service,” Pearce explained. “We can source and repair equipment on short lead times, and this project entailed sourcing a new pre-cast 1000 L polyethene tank, two new pumps with motors, new non-return and gate valves as well as pipework, electrics and controls.” Rotamec also relied on its in-house fabrications department to expedite the project. A 160 mm high steel frame was designed and constructed to raise the new tank off the floor, which allowed for easier integration of the new system into existing pipework. This simplified the layout of the pipework too. Each new pump features an open impeller, optimal for pumping wastewater, driven by a 5.5 kW motor that provides greatly improved efficiency compared to the previous units, unlocking energy cost savings. The new tank eliminated any leaks or seepage, ensuring that the basement no longer required cleaning. The project was completed within three weeks. Pumping system solution