Linear Position Sensors Provide Accurate Position Feedback of Steam Control Valves

April 24, 2009 - PRLog -- Constructed of stainless steel, the HSTAR 750 Series Hermetically Sealed Position Sensors can withstand 400º temperature spikes and exposure to radiation at 3x107 Rads for 40 years.  

These ¾" (19 mm) diameter AC-operated linear position sensors are being implemented in the rehab of power generation plants to better monitor the position of controls for increased efficiency and reduced operating costs.  In a typical power plant, steam turbines can contain a number of control valves - a reheat stop value, an interceptor valve, a governor valve, and a throttle valve.  Plant operators must always know the position of governor and throttle valves and the position at start up and shut down of reheat stop and interceptor valves. Typically, theses valves are fully open or fully closed, depending on the turbine start/stop status.  As modulating valves, the governor and throttle valves might be 25 or 40 percent open, depending on power generation requirements. Typically, plants have very precise control schemes for valve position to increase operating efficiency and save fuel. As many turbines date back half a century, the HSTAR Position Sensors are being implemented in plant rehabs to provide more reliable position feedback of control valves.  

Operating within the harsh environment of a power or steam plant, the HSTAR Position Sensors provide highly accurate position feedback of valve position, providing output to remote electronics that can be monitored by operators.  Available in ranges of ±0.050 inch (±1.25 mm) to ±10.0 inches (±250 mm), sensors feature high resolution, excellent repeatability, and low hysteresis as well as the highest sensitivity consistent with good linearity.

Electrical termination of the HSTAR 750 Series is made through a sealed radial connector located near one end. The radial connector results in a through-bore design that permits access to either or both ends of the unit’s core for better mechanical support and core guidance, and easier cleanout in dusty or dirty locations.  The radial connector also has a shorter installed length, making the length of the HSTAR 750 Series sensors at least 2” shorter than comparable units with an axially mounted connector for easier installation in tight spaces.

Macro Sensors offers several standard options for HSTAR 750 units including metric threaded cores, smaller diameters and low mass cores. On special order, the HSTAR 750 sensors can be constructed for immersion in pressurized fluids.

For information, contact Macro Sensors at postionsensors@macrosensors.com  or refer to the web site at http://www.macrosensors.com/lvdt_macro_sensors/lvdt_produ... .

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Macro Sensors’ extensive line of linear and rotary sensors are used for position measurement and feedback in a variety of industrial applications including factory automation, motion control systems, metal fabricating, automotive assembly as well as power plants, gas/steam turbines. Incorporated in 1994, the Company offers more than 200 years of cumulative design and manufacturing experience by its key staff in serving its OEM and end-user international customer base. On June 1, 2005, Macro Sensors was acquired by AST, manufacturer of state-of-the-art (Micro Electro Mechanical Structures) MEMS-based pressure sensors, transducers, and transmitters. Common applications of AST sensor products are in industrial OEM, hydraulic systems, fuel cells, medical gases, HVAC/R, refrigeration, oil & gas exploration/production, and off-road vehicles. For more information on AST products and technology, visit the AST website at www.astsensors.com.