Bently Nevada 135613-02 | Case Expansion Transducer | Turbine Thermal Growth Measurement

Description

Bently Nevada 135613-02 | High-Temperature Case Expansion Transducer | LVDT Measurement

Key Technical Specifications

The published Bently Nevada specification identifies the 135613-02 configuration with a 50.8 mm measurement range and approximately 241 mm overall mechanical length. The same documentation specifies 200 Hz typical frequency response, 0.125% full-scale stability, and less than 0.25% full-scale non-linearity.

Product Introduction

What the Bently Nevada 135613-02 Does

The Bently Nevada 135613-02 is a high-temperature case expansion transducer used in turbine supervisory instrumentation to measure thermal growth of a machine casing relative to its foundation. The measurement is particularly important during turbine startup, loading, and thermal stabilization, when casing movement can affect clearances and machine alignment.

This is an LVDT-based displacement measurement device, not a 3300 XL proximity probe. The published 135613 documentation gives the -02 configuration a 2.00 in (50.8 mm) linear range and a 0.10 V/mm electrical scale factor.

135613-02

Application Scenarios & Field Pitfalls — Engineer’s Perspective

Engineering Pain Point

Large steam and gas turbines experience significant thermal expansion between the casing and its fixed reference points. A case expansion measurement system provides the control and protection system with an indication of this relative movement, allowing engineers to evaluate abnormal thermal behavior before it develops into a mechanical clearance or alignment problem.

Typical Applications

• Steam turbine TSI: Monitoring casing growth during startup and load changes.
• Gas turbine auxiliary monitoring: Measuring structural thermal movement where a case-expansion channel is part of the machinery monitoring scheme.
• Large rotating machinery: Providing displacement information to a plant’s turbine supervisory instrumentation system.
• Turbine commissioning: Establishing expected thermal expansion behavior and comparing subsequent startups against baseline measurements.

Technical Pitfalls to Avoid

1. Do not substitute a proximity probe based only on displacement range.
   The 135613 is an LVDT case-expansion transducer. Its mechanical installation, electrical scaling, and associated instrumentation are different from a conventional shaft proximity measurement channel.
2. Check the complete part-number configuration.
   Documentation for the 135613 family distinguishes several configurations. The -02 option corresponds to a 50.8 mm range, while other suffixes provide different mechanical arrangements or ranges. Confirm the complete ordering code before purchasing a replacement.
3. Do not judge compatibility from the sensor body alone.
   The transducer must match the associated case-expansion signal-conditioning and monitoring architecture. Check the existing wiring diagram, excitation/scaling requirements, mechanical mounting, and turbine TSI documentation before installation.

Related Products

• Bently Nevada 135613-01 — Same case-expansion transducer family with a different linear-range configuration.
• Bently Nevada 135613-03 — 135613 family configuration with a larger mechanical range.
• Bently Nevada 135613-11 — Alternative 135613 configuration for case-expansion installations.
• Bently Nevada 135613-12 — Related 135613 configuration with the 50.8 mm linear range but different mechanical arrangement.
• Bently Nevada 24765-02-01 — Related case-expansion transducer assembly family used for turbine thermal growth measurement.
• Bently Nevada 24765 series — Case-expansion measurement family intended for large turbine applications.

The 135613 and 24765 families are specifically associated with thermal case/shell expansion measurement, so they should not be treated as interchangeable with shaft vibration probes merely because both appear in turbine machinery protection inventories.

Procurement Verification

For a replacement 135613-02, verify these items against the installed unit before issuing a purchase order:

• Complete nameplate and suffix
• 50.8 mm measurement-range requirement
• Mechanical mounting dimensions
• LVDT signal-conditioning hardware
• Existing turbine TSI cabinet/channel
• Cable and termination arrangement
• Calibration status
• Physical condition of the extension rod and housing
• Original equipment drawing or machinery monitoring documentation

Important: Some current online listings incorrectly describe 135613-02 as a 3300 XL proximity probe or as a vibration-monitoring module. Those descriptions conflict with the Bently Nevada 135613 case-expansion documentation. The safer identification is High-Temperature Case Expansion Transducer, DC LVDT.