Food & Drink Process & Packaging Issue 28 2020 | Page 34

Smart Position Transmitters for Enhanced Plant Operational Efficiency Maximum process reliability and constant product quality are maxims in the food industry - whether in the manufacture of beverages, sweets and dairy or in meat processing. The increased usage of automation within the Process Industries has had a significant effect on the nature of valves supplied into the sector. Whilst the functions of the valve and valve actuator are fundamentally the same regardless of whether the automated valve is being used for control (modulating) or for by the Plant Operator until the product When mounting a rotary transmitter On/Off operation, the equipment that is already in service and performance is on a linear valve, a non-linear output is interfaces between the control room and not as expected. often generated due to a linear to rotary the valve differ depending on the valve conversion kit being used. Smart IVPTs function. A few specialist companies providing Control valves will typically employ a such as Imtex Controls Limited, have Positioner to initiate a valve movement recognised both the potential benefits and a Position Transmitter to confirm to Plant Operators for using IVPTs on valve position matches required position. valves but also the severe limitations of On the other hand, an On/Off Valve will the products currently available. For this connect using a Solenoid Valve to allow reason, new ‘smart’ solutions are now Another benefit of Smart IVPTs is that a change in a digital output status in being offered that solve the traditional they put intelligence in the field device. the PCS to operate the valve and a Limit issues of IVPTs and enable plant The ST-4312 NC Transmitter from Imtex Switch Box to confirm the valve is in the operators to maximise their returns Controls analyses the stroking speed required position. from these devices. of the valve every time it moves and In contrast, the Position Transmitter The new generation of smart IVPTs on a Control Valve has been largely employ more robust feedback overlooked and hence many control mechanisms. For example, the Imtex valves suffer performance issues NC transmitter range utilises inductive solely because of the limitations of the sensor technology in non-contact, solid position feedback mechanism and can state feedback devices that are both have a significant effect on both plant highly accurate and largely impervious With the ever increasing need to improve productivity and plant safety. to challenges presented by the plant efficiency and safety, Independent environment in which they operate. Valve Position Transmitters provide a Valve Position Monitoring solutions, The vast majority of Position Transmitter products currently available Traditional IVPTs are often tricky to utilise a potentiometer, which have a calibrate, requiring the use of tools number of limitations when used on or a laptop to complete the setting of valve applications. Potentiometers are zero and span. Smart IVPTs simplify susceptible to vibration, wear and liable the calibration by allowing the user to to contamination from foreign particles calibrate through push buttons built into such as dust, sand or water. the transmitter unit. In addition, where the smart IVPT is equipped with the These issues, along with those ability to interface with a digital protocol encountered with other transmitter such as HART, the device might also be technologies are often not appreciated calibrated remotely. 34 FDPP - www.fdpp.co.uk have recognised this issue and provide the means to adjust the output from the device. For example, the Imtex NC transmitter is available with the ability to set up to 20 intermediate feedback points to linearise the output. compares this information with a stored ‘as new’ profile of the valve. The device is then capable of sending a warning signal via the HART communication interface, flagging when the valve has started to slow down by a user defined amount. simple and cost effective method to deliver these demands. By employing the latest generation of ‘smart’ IVPTs, plant operators are able to dramatically improve their efficiency and safety by gathering information on valves that permits targeted preventative maintenance. www.imtex-controls.com