What Is an I/P Converter? How 4–20 mA Controls Pneumatic Valves

Industrial Current to Pressure Converter – Fairchild TD6000 Series

In modern industrial automation, electronic controllers like PLCs and DCS systems often need to operate pneumatic control valves. This is where an I/P Converter — also called a Current to Pressure Converter — plays a critical role.

What Is an I/P Converter?

An I/P Converter (Current-to-Pressure Converter) is an electro-pneumatic device that converts an electrical control signal, typically 4–20 mA, into a proportional pneumatic output such as 3–15 PSI.

This conversion allows electronic control systems to accurately regulate pneumatically actuated control valves, dampers, and positioning devices.

Why 4–20 mA and 3–15 PSI Are Industry Standards

The 4–20 mA current loop is widely used in industrial environments because it is resistant to electrical noise and allows fault detection. Similarly, 3–15 PSI is the most common pneumatic control signal used in valve actuators.

An I/P Converter bridges these two standards, ensuring smooth and reliable control.

How Does an I/P Converter Work?

Inside an I/P converter, the incoming 4–20 mA signal energizes an electromagnetic coil. This force controls a flapper-nozzle mechanism that regulates air pressure. The regulated air pressure is then amplified through a pneumatic relay to produce a stable output pressure.

As the input current increases, the output pressure rises proportionally, for example:

• 4 mA → 3 PSI
• 12 mA → 9 PSI
• 20 mA → 15 PSI

Typical Applications of I/P Converters

• Pneumatic control valves
• Process automation loops
• PLC and DCS-based systems
• Oil & gas plants
• Chemical and petrochemical industries
• Power plants and utilities
• Water and wastewater treatment plants

Key Benefits of Using a High-Quality I/P Converter

• Precise valve positioning
• Improved process stability
• Noise immunity in industrial environments
• Reduced calibration drift
• Reliable operation in continuous-duty applications

Choosing the Right I/P Converter

When selecting an I/P converter, consider:

• Input signal compatibility (4–20 mA, voltage)
• Output pressure range (3–15 PSI, 6–30 PSI, etc.)
• Accuracy and repeatability
• EMI/RFI immunity
• Mounting options (panel, DIN rail, pipe)
• Environmental conditions (temperature, vibration)

Industrial-Grade Solution: Fairchild TD6000 I/P Converter

The Fairchild TD6000 Series I/P Converter is widely used in critical industrial control applications due to its high accuracy, rugged construction, and stable long-term performance.

It converts 4–20 mA to 3–15 PSI with excellent repeatability and is suitable for demanding process environments.

👉 View Fairchild TD6000 I/P Converter on IndiaMeters

Conclusion

An I/P converter is a critical link between modern electronic control systems and traditional pneumatic equipment. By selecting a high-quality current-to-pressure converter, industries can achieve accurate, reliable, and repeatable control of pneumatic valves and actuators.

For genuine industrial I/P converters with expert support, IndiaMeters offers proven solutions trusted by engineers across India.