BENTLY NEVADA as a brand under General Electric (GE), is a leading global supplier of mechanical condition monitoring and protection systems. The BENTLY 3500 series is a modular monitoring system designed specifically for industrial equipment, widely used for the protection and status monitoring of critical units. This system combines high-precision sensors, powerful signal processing capabilities, and flexible communication interfaces to provide real-time data collection, fault diagnosis, and alarm management, helping users optimize equipment operation, extend equipment lifespan, and reduce maintenance costs.

2. Main functions and advantages of BENTLY 3500 series
2.1 Core Functions
Vibration monitoring: Measure shaft and bearing vibrations through eddy current sensors, accelerometers, etc., and analyze mechanical imbalances, misalignment, looseness, and other faults.

Displacement monitoring: Monitor axial displacement, differential expansion, etc. to prevent friction between the rotor and stator.

Temperature monitoring: Monitor bearing temperature, lubricating oil temperature, etc. to avoid overheating and damage.

Speed/phase monitoring: used for start stop analysis and torsional vibration monitoring.

Dynamic data collection: supports waveform and spectrum analysis to assist in fault diagnosis.

Alarm and protection: Provides multi-level alarms (warning, danger) and can be linked to shutdown protection.

2.2 Technical advantages
Modular design: monitoring channels can be flexibly configured according to requirements and support expansion.

High reliability: Compliant with international standards such as API 670, suitable for harsh industrial environments.

Intelligent diagnosis: Combining expert systems to provide root cause analysis of faults.

Industrial communication integration: Supports protocols such as Modbus, Profibus, OPC, and seamlessly integrates with DCS/PLC.

Remote monitoring: Data can be accessed remotely through the network, supporting predictive maintenance.

3. Typical industry application cases
Case 1: Monitoring of Centrifugal Compressors in Petrochemical Plants
The cracking unit of a large petrochemical enterprise uses multiple high-pressure centrifugal compressors. Due to long-term high load operation, rotor dynamic balance problems occur frequently, and unplanned shutdowns were caused by excessive vibration, resulting in single losses exceeding one million US dollars.

Solution:

Deploy BENTLY 3500 system, equipped with 3500/42M vibration monitoring module and eddy current sensor, to monitor compressor bearing vibration in real time.

Set multi-level alarm thresholds to trigger an alarm when the vibration value exceeds 4.0 mm/s (warning) or 6.3 mm/s (danger).

By combining spectrum analysis, the characteristics of rotor imbalance were discovered, and dynamic balance correction was arranged in advance to avoid sudden failures.

effect:

Unplanned equipment downtime is reduced by 60%, and annual maintenance costs are reduced by approximately 30%.

Through trend analysis, the maintenance cycle has been optimized, and the operating life of the equipment has been extended by 20%.

Case 2: Differential Expansion Monitoring of Power Plant Steam Turbine
The 300MW steam turbine of a certain thermal power plant was severely damaged due to uneven thermal expansion, which caused friction between the rotor and cylinder. Traditional monitoring methods cannot accurately capture changes in inflation.

Solution:

Adopting BENTLY 3500 system, integrating 3500/45 axial displacement/differential expansion module to monitor the relative displacement between rotor and cylinder.

Set the differential expansion alarm threshold (± 1.5 mm) and adjust the thermal expansion effect based on temperature data.

By comparing historical data, optimize the start-up temperature curve to avoid dynamic friction.

effect:

Successfully prevented multiple friction risks and reduced the start-up time of the unit by 15%.

The reliability of the equipment has significantly improved, and the annual maintenance cost has been reduced by 25%.

4. BENTLY 3500 series representative models and parameters
(1) 3500/42M Four Channel Vibration Monitoring Module
Function: Used for radial vibration monitoring, supporting input of velocity or acceleration signals.

Key parameters:

Measurement range: 0-20 mm/s (RMS) or 0-200 μ m (peak).

Frequency response range: 10 Hz~1 kHz (expandable to 10 kHz).

Accuracy: ± 1% FS (full scale).

Alarm output: 4-20 mA analog signal, relay contact.

(2) 3500/45 Axial Displacement/Differential Expansion Monitoring Module
Function: Monitor rotor axial displacement or turbine expansion difference.

Key parameters:

Measurement range: ± 2 mm (standard), customizable ± 10 mm.

Resolution: 0.1 μ m.

Linearity: ± 0.5% FS.

Output: Dual channel independent alarm, supporting Modbus RTU communication.

(3) 3500/22 Temperature Monitoring Module
Function: Used for temperature monitoring of bearings, lubricating oil, etc.

Key parameters:

Input type: RTD (PT100) or thermocouple (K-type).

Measurement range: -50 ℃~400 ℃ (RTD), 0 ℃~800 ℃ (thermocouple).

Alarm accuracy: ± 1 ℃.

5. Summary
The BENTLY 3500 series, with its high precision, modularity, and intelligence, has become a benchmark solution for industrial equipment condition monitoring. Whether it is vibration management of petrochemical compressors or differential expansion control of steam turbines, this system can provide reliable data support and fault warning, helping enterprises achieve predictive maintenance and intelligent operation and maintenance. In the future, with the development of Industry 4.0 and Internet of Things (IIoT) technology, the BENTLY 3500 series will further integrate big data analysis to drive the industry towards a more efficient and secure direction.