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