I/P and E/P Transducers

I/P and E/P transducers deliver a pneumatic output
proportional to an electronic input signal.
Image courtesy Rotork Instruments - Fairchild

Converting from one signal type to another is a common challenge in process control. When the application calls for conversion from an electrical signal, current or voltage, to a pneumatic signal (pressure), this calls for an I/P or E/P transducer.

I/P and E/P transducers are electro pneumatic devices that convert current or voltage input signals to a linearly proportional output pressure. These transducers are available in a wide array of configurations to accommodate almost any industrial setting or application.

The transducers pictured use, in the pilot stage, electronic closed loop feedback and a piezoceramic actuator flapper nozzle system, controlling the signal pressure of an integral pneumatic volume booster. A control diaphragm and main valve on the volume booster section controls the flow of air at the output in response to the pressure received from the pilot stage. The output pressure of the volume booster is feed into an electronic closed loop feedback arrangement to deliver accurate pressure control.

Applying the transducer is a straight forward operation, involving matching the device input and output signal capabilities with those of the application. More detail is provided in the document included below.

Share your process measurement and control challenges with instrumentation specialists, combining your process expertise with their product knowledge to produce effective solutions.

Electro-Pneumatic Transducer for Process Control from MSJacobs-Cali

Zero Bleed Pneumatic Controller for Valve Actuators and Other Process Control Apps

This video shows the components of the BiFold Zero Bleed Pneumatic controller. Called "PICO", this unit was first described in a previous article. Check out the video, as it nicely lays out the various operating components of a complete system. More information is available from product application specialists, with whom you should share your valve control and actuation challenges to get positive and effective solutions.

Zero Bleed Pneumatic Controller

The PICO consists of a single logic control head
and a digital filter booster
Courtesy Bifold - Rotork

The Bifold brand, under the Rotork corporate umbrella, developed a true zero bleed pneumatic position controller for valve actuators. The product, called PICO, consists of a single logic control head and a digital filter booster. The control head unit provides bluetooth communications, ESD monitoring and control, graphic display, integral valve feedback measurement, low power modes, a partial stroke test feature and local control setting switch. The properly installed assembly is suitable for use in hazardous locations.

The new control unit is capable of fulfilling applications employing positional control, on/off and ESD (emergency shutdown) valves. The filter booster allows the small size of the PICO to deliver the flow rate of a substantially larger system of conventional design.

The PICO, with control head and filter booster
shown installed on pneumatically actuated valve
Courtesy Rotork - Bifold

The PICO provides a number of operational benefits to pneumatic actuated valve applications. More information is available from product application specialists, with whom you should share your valve control and actuation challenges to get positive and effective solutions.

Pneumatic Volume Booster Function

Pneumatic Volume Booster
Fairchild

A volume booster is used in a pneumatic control system to relay a low flow signal as one with greater flow volume. The common configuration is to provide a 1:1 ratio between the input and output pressure, keeping the input and output signals the same pressure. Products are available that deliver different ratios.

The general purpose of a volume booster is to provide a relay between a system with low flow volume and one with higher volume requirements. A typical example is a pneumatic actuator. The flow available through the pneumatic signal line may be insufficient to deliver the response rate desired from the pneumatic actuator. A volume booster, with control over an independent air supply, solves this challenge with increased flow volume at the same pressure as the control signal.

Volume boosters are simple in operation. The input signal applies force to one side of a diaphragm, the output pressure to the other. An imbalance between the two applied pressures will cause the diaphragm to move, changing the position of the valve and the outlet pressure until the two forces are again in balance. Little maintenance is required when the units are properly installed and supply air is of good quality.

The unit pictured is from Fairchild, a well recognized manufacturer of industrial pneumatic components, and provides a 1:1 ratio. There are some key points in the selection process, so reach out to a product specialist with your pneumatic system challenges and requirements. Combining your process and facility knowledge with their product application expertise will produce effective solutions.

Volume Booster for Pneumatic Control Signal from MSJacobs-Cali