The Bently Nevada 330851-02-000-060-50-00-05 is a 3300 XL 25 mm Proximity Probe designed for high-precision, non-contact measurement of differential expansion in large rotating machinery. As part of the 3300 XL 25 mm Transducer System, this probe provides a linear range of 12.7 mm (500 mils), making it ideal for monitoring the thermal growth differences between turbine rotors and machine casings.

Features

• Extended linear range of 12.7 mm (500 mils) for large displacement monitoring.
• Dual-Seal design with FluidLoc cable technology to prevent fluid migration.
• PEEK probe tip construction with an AISI 304 stainless steel case for durability.
• Extreme temperature survivability up to 250 degC.
• Standard sensitivity of 0.787 V/mm (20 mV/mil).

Applications

• Steam Turbine Generators: Monitoring thermal growth and internal clearances.
• Large Industrial Gas Turbines: Tracking rotor behavior under high-temperature cycles.
• High-Capacity Process Compressors: Measuring axial movement and shaft expansion.
• Heavy-Duty Industrial Pumps and Motors: Preventing mechanical rubbing in high-horsepower machinery.

Technical Specifications

Installation Guidelines

• It is highly recommended to install the probe into an official Bently Nevada Sliding Bracket Assembly to allow for proper positioning and calibration.
• The base plate should be securely bolted to the turbine casing structure.
• The probe sits within a moveable sliding carriage, which allows technicians to simulate shaft collar movements and verify electrical scaling without opening the turbine housing.
• Ensure the probe is handled with care to avoid damage to the PEEK tip.
• Verify that the cable routing is protected from high-EMI sources and mechanical stress.

FAQ

What is the primary application of a 25 mm proximity probe?

Unlike standard 8 mm probes used for radial vibration, the 25 mm probe is specifically engineered for differential expansion measurements where larger physical displacement ranges are expected.

What is the sensitivity and scale factor?

The standard scale factor for this 3300 XL 25 mm probe system is 0.787 V/mm (20 mV/mil).

What are the operating temperature limits?

The probe head and its integrated FluidLoc triaxial cable are designed for extreme conditions, supporting a continuous operating temperature range from -35 degC to +200 degC (-31 degF to +392 degF).