WOODWARD 9907-1253

الوصف

The WOODWARD 9907-1253 is not a traditional mechanical actuator. Instead, it’s a sophisticated CPC-II Current-to-Pressure Converter (also sometimes referred to as an electrohydraulic pressure-regulating valve control).

WOODWARD 9907-1253: CPC-II Current-to-Pressure Converter

The WOODWARD 9907-1253 is a critical component in industrial control systems. Its primary function is to accurately convert a standard electrical control signal (typically 4-20 mA) into a precise hydraulic pressure output. This controlled pressure is then used to accurately position single-acting steam turbine governor valves.

Product Overview

This particular part number designates a specific configuration within Woodward’s advanced CPC-II (Current-to-Pressure Converter, Generation II) series. CPC-II units are highly regarded for their exceptional accuracy, high resolution, and robust design, making them ideal for demanding industrial environments.

• Product Type: Current-to-Pressure Converter / Electrohydraulic Pressure-Regulating Valve Control
• Manufacturer: Woodward
• Part Number: 9907-1253
• Model Designation: CPC-II
• Function: It takes a 4–20 mA pressure demand signal from an electronic control system (like a turbine controller or Distributed Control System – DCS) and precisely regulates hydraulic oil pressure. This controlled pressure is then applied to position single-acting steam turbine governor valves.
• Output Pressure Range: 0 to 25 bar (0 to 363 psi).
• Design Specifics: This model is built for single-acting operation, meaning it controls pressure to move a valve in one direction, with a spring providing the return force. It is also rated for use in Zone 2 hazardous environments and offers dual redundant capability.

Detailed Product Description

Woodward’s CPC-II series, including the 9907-1253, is engineered for high performance and reliability, particularly in steam turbine applications. Key features and characteristics include:

• Precise Pressure Control: The unit incorporates a highly accurate internal pressure sensor and a PID (Proportional-Integral-Derivative) controller. This combination ensures precise and stable control over the output oil pressure, directly translating to accurate positioning of the turbine valve.
• “Dirt Buster” Technology: A notable feature of the CPC-II is its robust design, often called “Dirt Buster” or “Silt Buster” technology. It includes a strong actuator, corrosion-resistant materials, a unique single-moving rotary valve, and a self-cleaning port design. This technology makes it highly resistant to dirty or contaminated oil (capable of handling up to ISO20/16 cleanliness), which is a common issue in industrial hydraulic systems, thereby improving reliability by preventing silt buildup.
• Enhanced Dynamics: The CPC-II features enhanced dynamics, meaning it’s designed for rapid and stable response to changes in control signals, crucial for effective turbine speed and load control.
• Redundancy Capabilities: This particular model (9907-1253) supports dual redundant inputs/sensors and can be configured for dual-redundant (master/slave) CPC applications. This significantly enhances system reliability and availability in critical applications where turbine uptime is paramount.
• Fail-Safe Mechanism: In the event of an internal unit failure, loss of electrical input power, pressure sensor failure, or processor failure, an internal valve-return-spring forces the CPC to a failsafe position. For this model, it typically ensures the safe closure of turbine control valves.
• Manual Stroke Function: It includes a manual stroke screw, allowing for local manual adjustment of the output pressure (and thus turbine valve position) for maintenance or emergency situations. It can also be controlled remotely or locally via a PC-based service tool.
• Diagnostic Features: The CPC-II provides status indications for pressure sensor health, input demand signal health, internal unit health, and input power quality, allowing operators to monitor its operating status effectively.
• Certifications: As a product designed for industrial environments, it carries relevant certifications for hazardous area classifications (e.g., ATEX, IECEx, CSA, Zone 2).

Technical Specifications

Typical Applications

The WOODWARD 9907-1253 CPC-II Current-to-Pressure Converter is primarily used in heavy industrial applications requiring precise and stable control of steam valves:

• Steam Turbine Valve Control: Its core application is to accurately position the control valves of single-acting steam turbines, which directly regulates steam flow, impacting turbine speed and power generation.
• Turbine Speed and Load Control: By providing precise control over steam admission, it directly contributes to the stable control of turbine speed and the efficient management of electrical load in power generation.
• Power Generation Plants: Integrated into the control systems of steam power plants, especially where high reliability and redundancy are required.
• Petroleum and Chemical Industries: Utilized in processes that rely on steam turbines for power or compression.