Product Overview

The Bently Nevada 24765-01-00 is a high-precision DC Linear Variable Differential Transformer (LVDT) engineered specifically for measuring the thermal growth and structural expansion of large machinery casings. As a core element of Turbine Supervisory Instrumentation (TSI), this transducer tracks the relative displacement between the machine foundation and the turbine housing. By providing accurate, real-time data on casing movement, the 24765-01-00 ensures that thermal expansion occurs symmetrically, preventing internal alignment shifts and mechanical rubs that could lead to catastrophic equipment failure. Its solid-state DC design integrates the necessary electronics within the assembly to deliver a linear analog voltage output directly proportional to the core's physical position.

Key Technical Characteristics

The 24765-01-00 is built to withstand the rigorous thermal and mechanical stresses associated with power plant and heavy industrial environments while maintaining exceptional signal stability.

• Model Number 24765-01-00

• Measurement Range 1.0 inch (25.4 mm) total stroke

• Transducer Type DC-operated Linear Variable Differential Transformer (LVDT)

• Electrical Scale Factor 8.79 V/in (0.346 V/mm)

• Linearity Performance ±0.5% of full-scale range

• Signal Stability ±0.125% of full-scale range

• Frequency Response −3 dB at 20 Hz

• Operating Temperature −18°C to +71°C (0°F to +160°F)

• Physical Dimensions 241 mm x 117 mm x 88.9 mm

• Assembly Weight 2.3 kg (approx. 5.1 lbs)

• Output Signal Proportional analog DC voltage

Industrial Applications and Operational Use Cases

The primary function of the 24765-01-00 is to facilitate safe thermal transitions in high-performance rotating assets. It is widely deployed across the following scenarios:

• Steam Turbine Monitoring Tracking the axial growth of the turbine shell during heat-up and cool-down cycles to ensure the sliding feet are moving freely and not "binding."

• Gas Turbine Shell Expansion Providing feedback to control systems regarding the thermal expansion of the outer casing to maintain critical internal clearances.

• Large Centrifugal Compressors Monitoring structural displacement in high-pressure applications to detect potential piping strain or foundation shifts.

• Predictive Maintenance Utilizing displacement trends to identify lubrication issues or debris buildup in the machine's sliding foundation supports.

• TSI Integration Interfacing directly with Bently Nevada 3500/45 Position Monitors to provide automated alarm and shutdown logic based on expansion limits.

The robust industrial housing protects the sensitive LVDT core from contaminants, while the precise electrical scale factor allows for seamless integration with plant-wide Distributed Control Systems (DCS), ensuring long-term reliability in critical machinery protection loops.