Valve sensors and valve positioners
Valve sensors provide real-time monitoring of valve position and verify that a valve reaches its commanded open or closed state. Valve sensors are installed on quarter-turn pneumatic actuators and provide position feedback to a PLC or control system. These actuators are typically used for process control in industrial automation and food and beverage applications. Typical applications include tank farms, diverter valves, valve skids and valve banks. By confirming the true mechanical position of the actuator, valve sensors help prevent false signals, such as indicating a valve is closed when it has not fully reached the closed position.
Several types of valve monitoring and control devices are used in these applications:
- Discrete valve sensors detect basic valve positions, such as open or closed.
- Smart valve sensors monitor valve position and provide additional data such as cycle counts, device status, and diagnostics.
- Valve positioners actively control the valve position by adjusting actuator pressure in response to a command signal.
ifm is your one-stop shop for valve feedback, monitoring, and control needs.
Explore our valve solutions below.
Evolution of valve feedback systems
Valve position feedback systems range from basic visual indication to advanced monitoring and control solutions. Different areas of the plant may use different methods of feedback.
- No feedback, visual indication only.
- Switchboxes using mechanical limit switches.
- Non-contact inductive sensors which signal open or closed positions only.
- Non-contact continuous position monitoring
- Continuous position monitoring with direct (open/close) solenoid control
- Continuous position monitoring and valve positioning
| MVQ101 | MVQ201 | MVQ valve positioner | ||
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| Valve actuator type | Spring-return |  |
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| Double-acting | |
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| Diverter valve | |
3 digital outputs only via IO-Link |
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| Manual valve | |
Yes but not necessary |  |
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| Monitoring range | 360º continuous monitoring | 0...100% (90º) | ||
| Accuracy | 0.1º | Position feedback accuracy: 1º Position control accuracy: 0.5%...2% adjustable |
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| Main feature | Smart sensor with diagnostics | Solenoid outputs for direct control + smart sensor with diagnostics |
Modular design with precision position control capability for modulating applications + smart sensor diagnostics |
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| Output functions | 3x digital outputs | 2x digital outputs | - | |
| SIO (standard I/O) available | |
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| IO-Link enabled | |
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(B-port only) | |
| Mounting dimensions | 80 x 30 x 20 mm* | Sensor: 80 x 30 x 20 mm* Solenoids + Throttle plate: Standard NAMUR mounting interface |
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| Protection rating | IP65; IP67 | |||
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MVQ smart valve sensors | MVQ smart valve positioner | ||
*Adapter plates and brackets are available for larger actuators.
MVQ valve sensor can be mounted on any ISO Namur standard valve actuator
Smart valve sensor
ifm’s MVQ smart valve sensor uses magnetic sensing technology to continuously monitor valve position. It detects open and closed states, identifies closed-position drift, and tracks valve open and closed times. The sensor provides a continuous feedback signal and retains position data after power loss. This real-time information enables immediate correction of valve failure, helping prevent critical process contamination and unplanned stoppages.
Smart valve positioner
ifm’s smart digital valve positioner ensures the valve reaches its exact commanded position with high accuracy while providing both position feedback and control in a single unit. Automatic calibration and advanced diagnostics detect performance issues early. IO-Link communication enables remote configuration and monitoring, improves process stability and control-loop performance, reduces air consumption, and extends valve and actuator service life.
Valve sensor
ifm’s IN sensors use standard inductive technology to provide non-contact detection of metal targets. A typical inductive sensor contains a ferrite core surrounded by a coil of wire to form an inductive circuit. An IN sensor incorporates two ferrite coils. These coils are positioned vertically inside the housing. The rotating puck, which is mounted on the actuator stem, contains two stainless steel targets positioned on the side of the puck, 90° apart, at different heights.
As the valve opens, the puck rotates, moving one of the targets in front of one ferrite coil. The coil senses the target and provides a positive signal of valve-open position.
When the valve closes, the puck rotates and moves the second target in front of the second ferrite coil. The coil senses the target and indicates a positive valve-closed position.
ifm’s feedback systems are compatible with actuators using ISO NAMUR VDE 3845 standard mounting, which defines the threaded hole locations for sensor installation. ifm offers these products in AC and DC voltage, with local solenoid switching, for hazardous locations, and with integrated AS-i capability.
| DC | AC/DC | AS-i | Hazardous application | |
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| Main feature | Dual-coil inductive sensors in one housing for monitoring valve positions | |||
| Monitoring range | Open/close positions of rotary valves | |||
| Outputs | 2x Digital outputs | |||
| Electrical design |
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AC/DC selectable | AS-i | NAMUR intrinsically safe (requires amplifier) |
| IP rating | IP67 | |||
| Mounting: 30 x 80 mm | |
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| Mounting: 30 x 130 mm | |
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| Notes | Target puck is required to be mounted to the valve stem | |||
Select a puck or a puck kit according to the dimensions of your ISO Namur actuator.
- X and Y dimensions show the position of the standard mounting holes for the valve feedback sensor.
- Z is the height of the stem.
- B is the width of the bottom of the stem components (including washer, sealing ring etc.)
- May need puck with larger diameter.
Below you will see the dimensions of the 1. Sensor and 2. Puck and how they interact:
Manual valves are common in plants where automation is limited. While efficiency will be improved through automation, the cost to retrofit all valves with actuators and feedback devices could be cost prohibitive. ifm offers simple-to-use feedback solutions for most manual valves.
Automated valves use pneumatic or electrical power to open and close the valve. With a manually operated valve, you run the risk of an operator failing to fully open or close the valve. This can be very detrimental to your manufacturing process.
To solve this, ifm created hardware kits that mount on standard ISO top flange valves. With these kits, you can easily attach our flagship solution for two-position feedback.
