Bently Nevada 3500/77M Cylinder Pressure Monitor

The Bently Nevada 3500/77M Cylinder Pressure Monitor is a 4-channel monitor that accepts input from Bently Nevada approved pressure transducers, conditions the signal to make various pressure measurements for reciprocating compressors, and compares the conditioned signals with user-programmable alarms. The 3500/77M provides:

• Machinery protection by continuously comparing monitored parameters against configured alarm setpoints to drive alarms
• Essential machine information for operations and maintenance personnel

Each channel of the 3500/77M will provide eight measured variable values that relate to cylinder pressure operation. The five values that relate to a single chamber are as follows:

• Discharge Pressure
• Suction Pressure
• Maximum Pressure
• Minimum Pressure
• Compression Ratio

Features

• Accepts 1 to 4 channels
• Frequency response: 0 to 5.5 kHz
• Three measured variables:
• Peak rod compression
• Peak rod tension
• Degree of rod reversal
• Pressure accuracy:
• 0.5% from 0.5 to 10.0 volts at 77°F
• 1.0% from 0.5 to 10.0 volts over 22 to 150°F)
• Front panel LEDs: OK, TX/RX, Bypass

• Transducer power supply: 23.0 ±0.8 Vdc with 24.5 ma current limiting

General Introduction

Technical Features1

• Input Compatibility：It accepts input from Bently Nevada approved pressure transducers, ensuring reliable and accurate signal reception.
• Frequency Response：With a frequency response range of 0 to 5.5 kHz, it can effectively capture and process pressure signals within this range, providing detailed and timely pressure data.
• Accurate Pressure Measurement：The pressure accuracy is 0.5% from 0.5 to 10.0 volts at 77 °F and 1.0% from 0.5 to 10.0 volts over 22 to 150 °F, guaranteeing precise measurements across a wide temperature range.
• Measured Variables：Each channel provides eight measured variable values related to cylinder pressure operation. Five of them are discharge pressure, suction pressure, maximum pressure, minimum pressure, and compression ratio, while the other three are peak rod compression, peak rod tension, and degree of rod reversal.
• Transducer Power Supply：It offers a 23.0 ± 0.8 VDC power supply with 24.5 mA current limiting, providing stable power to the pressure transducers.
• Front Panel LEDs：The front panel is equipped with LEDs for OK, TX/RX, and bypass, providing visual indicators for the monitor's status and operation.

Functionalities

• Machinery Protection：By continuously comparing the monitored pressure parameters against user-programmable alarm setpoints, it can promptly trigger alarms when abnormal pressure conditions are detected, preventing potential damage to the machinery267.
• Data Provision：It supplies essential machine information for operations and maintenance personnel, enabling them to make informed decisions regarding equipment operation and maintenance267.

Applications

• Oil and Gas Industry：In oil and gas extraction and processing facilities, reciprocating compressors are widely used. The 3500/77M plays a crucial role in monitoring the cylinder pressure of these compressors, helping to optimize the compression process and prevent equipment failures.
• Chemical Industry：In chemical plants, where reciprocating compressors are used in various chemical reaction and material transportation processes, the 3500/77M ensures the safe and stable operation of these compressors by providing accurate pressure monitoring.
• Power Generation Industry：In some power generation systems, reciprocating compressors are utilized for specific gas compression tasks. The 3500/77M helps to monitor the cylinder pressure of these compressors, contributing to the reliable operation of the power generation equipment.