In critical applications, Woodward’s Current to Pressure Converters (CPC-II and CPC-DX Redundant Version) are electrohydraulic pressure regulating control valves used to position single-acting steam turbine valve servos and actuators. The superb accuracy and resolution of the packaged redundant CPC’s utilized in this skid make it ideal for steam turbine valve control. The skid’s automatic transfer logic make it ideal for applications requiring a high level of system reliability and availability.

The CPC-II and CPC-DX Redundant version accepts 4-20 mA pressure demand signals and accurately controls oil pressure to precisely position single-acting steam turbine governor-valves. Precise and stable steam valve control directly relates to improved steam turbine speed and load control and reduced system mechanical wear.

The CPC-DX Redundant version integrated design allows for a cost effective purchase and installation of one hydraulic assembly which provides all the isolation and support benefits of fully segmented current-to pressure converters. Hand isolation valves are included within the package to give users the capability to easily repair or replace each individual current-to-pressure converter.

Both automatic and manual transfer logic are available for use within this skid assembly, depending on the system’s design. This skid’s automatic transfer logic simplifies system design as it requires no external relay/switching logic to operate, minimizing both converter-to-converter and control-to-converter interface wiring. The CPC’s configurable alarm/shutdown logic allows users to easily configure which system conditions force an automatic transfer from the master CPC to the slave CPC.

Manual transfer functionality is also available for systems where users desire to switch between pressure converters via external logic or hand switches. Master selection discrete inputs are utilized to allow users to easily and quickly select the desired control CPC. Integrated oil pressure gauges allow users to visually understand which converter is in control and verify the skid’s output oil header pressure level. Discrete output relay contacts can also be connected to system indication (lights, lamps, plant DCS) to assist with system health monitoring.

This Redundant CPC skid includes two CPC-II converters configured in a master/slave configuration, where the master unit controls output pressure, and the slave unit tracks master unit operation, and smoothly takes control of output pressure should there be a failure with the master unit. Optionally users can switch between converters to verify unit operation, and, should there be a need, replace either converter “on-line”.

If you are interested in this new product, email us for a quote! Or check out the product specification for more information.

This announcement was originally made by Woodward Jan 19 2016.