Bentley 3300/70 Dual-Channel Valve Position Monitoring Module - Detailed Product Description

I. Product Overview

The Bentley 3300/70 is a dual-channel valve position monitoring module of the 3300 series TSI (Turbo-Supercharger Instrumentation) system under Baker Hughes. It is specifically designed for continuous monitoring of the opening degrees of critical control valves and safety shut-off valves in rotating machinery and process industries. It adopts a standard 19-inch rack-mounted modular structure and supports hot-swapping. It can be disassembled and replaced without power interruption to the system. This module is compatible with LVDT (Linear Variable Differential Transformer), potentiometers, and 4-20mA position sensor signals. It provides real-time valve position percentage display, high-precision signal conversion, programmable alarms, and analog output functions, in accordance with API 670 standards. Some models meet SIL 2 safety level requirements. The product is widely used in non-explosive areas of power, petrochemical, and metallurgical industries, and is suitable for critical valves such as main steam valves, regulating valves, extraction steam valves, bypass valves, and compressor anti-surge valves, enabling closed-loop monitoring of valve positions, fault warning, and safety interlock protection, ensuring the controllable valve status during the start-up, shutdown, and operation phases of the unit.

II. Model Coding Rules

3300: This is the classic 3300 series modular TSI system of Bentley, installed in a standard 19-inch cabinet rack, supporting multi-module combination expansion, centralized power supply, and hot-swapping.

70: Function code, defined as a dual-channel valve position monitoring module, equipped with two independent signal input channels, specifically for the opening (travel) measurement of control valves and safety valves. It is the core model of the 3300 series valve position monitoring.

Subsequent coding (configuration bits):

Bit 1 (Input Sensor Type): 01 = 5kΩ potentiometer (90°~300° full range rotation); 02 = 5kΩ potentiometer (50°~90° full range rotation); 03 = ±25mm LVDT (AC); 04 = 4-20mA current input.

Bit 2 (Output and Function): 00 = Basic type, with LED display and relay alarm; 01 = With 4-20mA analog output; 02 = With 0-10V analog output; 03 = Display-only type, without alarm function.

III. Core Functions

Dual-channel independent valve position monitoring: The two input channels circuits are completely isolated, without signal crosstalk. It can simultaneously perform continuous real-time opening degree measurement of two independent valves (such as main steam valve + regulating valve), achieving dual valve point monitoring with a single module, saving rack space, and suitable for multi-valve collaborative monitoring scenarios.

Compatibility with multiple types of sensors: Supports LVDT (AC ±5V/±10V), potentiometers (0-5kΩ/0-10kΩ), and 4-20mA current loop as the main position sensor inputs. It is suitable for different valve travel and installation conditions. Sensors can be directly interchanged without additional signal conversion modules.

High-precision measurement and real-time display: The measurement accuracy is ±0.5% of the full scale, with a resolution of 0.1% of the valve position, and a 10Hz update rate per channel. It can capture the tiny travel changes of the valve in real time; the front panel is equipped with two 20-segment LED light columns, providing intuitive display of 0-100% valve position, allowing data to be read locally without an upper computer.

All-round fault self-diagnosis: Built-in OK fault self-check circuit, monitoring sensor disconnection, short circuit, signal over-limit, LVDT excitation anomaly, etc. faults 24 hours a day. Precisely distinguish valve mechanical jamming from sensor circuit faults, reducing false alarms and false interlocks; the panel LED indicators synchronously display OK of channels, faults, and bypass status. Programmable multi-level alarm and interlock: Each channel can independently set two levels of alarm thresholds (high and low), with alarm delay ranging from 0 to 10 seconds that can be programmed, and filtering of instantaneous signal fluctuations; each channel is equipped with two SPDT passive relay contacts (warning / danger), and the entire machine has four alarm contacts, with a rated load of 250V AC/3A, which can be directly connected to the sound and light alarm circuit and the unit safety interlock circuit.

Standard analog output (optional): Optional 4-20mA or 0-10V DC analog output, corresponding to the valve position opening degree linearly (0% = 4mA/0V, 100% = 20mA/10V), which can be connected to the DCS/PLC system to achieve centralized monitoring and closed-loop control of valve position data.

Strong anti-interference and system integration: Internal metal shielding structure, electrical isolation of input, output, and power supply circuits, resisting electromagnetic interference from frequency converters and high-voltage equipment; supports internal bus communication of the 3300 system, compatible with System 1 monitoring software, enabling remote parameter configuration, trend analysis, fault record storage and query.

V. Technical Parameters Measurement parameters

Channel quantity: 2 completely independent isolated channels.

Measurement range: 0 - 100% of valve travel (can be scaled according to sensor range).

Measurement accuracy: ±0.5% of full scale, resolution 0.1% of valve position.

Update rate: 10Hz per channel (100ms per cycle).

Sensor compatibility: LVDT (±25mm/±50mm, AC excitation), potentiometer (0-5kΩ/0-10kΩ), 4-20mA current signal.

Alarm settings: Two-level alarms for high/low opening degree per channel, with delay time programmable from 0 to 10 seconds. Electrical parameters

Power supply: -24V DC (allowable fluctuation ±10%), powered by the backplane of the 3300 rack.

Power consumption: ≤3W, maximum working current 15mA.

Input impedance: Voltage mode > 1MΩ, current mode 250Ω.

Relay output: 4 SPDT passive contact points, 250V AC/3A, 30V DC/3A.

Analog output (optional): 4-20mA DC (accuracy ±0.1% of full scale), 0-10V DC.

Isolation performance: High-voltage electrical isolation between input/output/power supply, anti-common-mode interference ≥ 2500V AC.

Environmental and mechanical parameters

Operating temperature: -40℃~+70℃.

Storage temperature: -40℃~+85℃.

Relative humidity: 0%~95% (no condensation).

Installation method: Standard 19-inch rack slot installation of the 3300 series, supports hot swapping.

Shell material: Metal panel + flame-retardant engineering plastic, shock-resistant, corrosion-resistant, oil-resistant.

Protection level: IP20 (internal installation of the control cabinet).

Size: Standard 3300 module size, compatible with 19-inch rack slots.

Certification and compliance

Industry standards: Compliant with API 670 Rotating Machinery Monitoring and Protection Standards.

Safety level: Some models meet SIL 2 Safety Integrity Level.

Electromagnetic compatibility: CE certification, compliant with EN 61000-6-2, EN 61000-6-4 standards.

Explosion-proof level: Non-explosion-proof design, no built-in safety barrier, only applicable to non-flammable and non-explosive areas.

VII. Structural Design

The module adopts a standard rack-based modular structure, divided into the front panel, internal main circuit, and rear wiring terminals. The layout is compact, facilitating installation, wiring, and maintenance.

Front panel: Integrated with dual 20-segment LED light columns (displaying 0~100% valve position), power/OK/alarm/fault LED indicators, and operation keys. It allows for on-site viewing of valve position and alarm status, completing basic parameter configuration such as alarm threshold and range. The operation is intuitive and convenient.

Internal main circuit: Divided into two independent signal processing units, corresponding to two channels. Each unit integrates sensor signal conditioning, excitation drive (LVDT-specific), filtering, linearization, alarm comparison, relay drive, and analog output circuit. There is no electrical connection between channels, and a single-point failure does not affect the operation of the other channel.

Back wiring terminals: Partitioned layout, clearly dividing two channels of sensor input terminals, four channels of relay alarm terminals, analog output terminals, power terminals, and system communication interface. Terminal markings are clear, wiring is neat, facilitating on-site wiring, troubleshooting, and maintenance.

Hot-swappable design: The module and the backplane of the rack use gold-plated connectors, with reliable contact, supporting online insertion and removal. Replacing the module does not require shutting down the entire TSI system, reducing the impact of maintenance on the unit's operation.

VIII. System Compatibility

Hardware compatibility

Rack and power supply: Perfectly compatible with the 3300 series standard 19-inch rack, system power module, system monitoring module. Functional modules such as vibration, displacement, and speed functions of the same series can be mixed and installed to work collaboratively.

Sensing components: Compatible with LVDT (±25mm/±50mm), 5kΩ/10kΩ potentiometer, 4-20mA position transducer. The same type of sensors can be directly interchanged without re-calibration.

Output connection: Relay contacts can be connected to sound and light alarms, unit interlock circuits, DCS/PLC dry contact inputs; Analog output can be connected to DCS/PLC analog input module to achieve centralized monitoring of valve position data.

Software compatibility Configuration software: Compatible with the 3300 series dedicated configuration software, it supports remote parameter configuration, alarm logic editing, sensor calibration, and firmware upgrade.

Monitoring software: Compatible with the System 1 equipment status monitoring software, it can achieve real-time valve position data collection, trend curve display, fault record storage, report generation, and remote access, supporting full lifecycle management of valves.

VII. Typical Application Scenarios

Power industry: Monitoring the opening/closing status of main steam valves, high-pressure regulating valves, low-pressure regulating valves, extraction steam stop valves, bypass valves in thermal power plants, and real-time feedback of valve start/stop and regulation status, warning of valve jamming, insufficient stroke, internal leakage, etc., to ensure safe start/stop of the unit and stable load.

Petrochemical industry: Position monitoring of non-explosion-proof centrifugal compressors' anti-surge valves, vent valves, process cut-off valves, and steam turbine control valves in non-explosion-proof areas, achieving closed-loop verification of valve opening/closing status, preventing valve misoperation caused by process fluctuations or equipment damage.

General industry: Monitoring the opening/closing status of large-scale fans and drive motors in metallurgy, cement, papermaking and other industries, as well as the opening/closing status of key cut-off valves in water treatment systems, ensuring that the valves operate correctly and reducing equipment failure and process accident risks.

VIII. Installation and Maintenance Specifications

Installation Requirements

Frame Installation: Insert the module smoothly into an empty slot of the 3300 frame, ensure that the gold-plated connector at the rear is fully engaged, tighten the panel screws to prevent loosening.

Sensor Wiring: Connect the LVDT / potentiometer / 4-20mA sensor cables to the corresponding input terminals according to the channel number. Ensure the wiring is secure, single-ended grounding of the shielding layer, and avoid interference.

Alarm and Output Wiring: Connect the relay contacts to the alarm/interlock circuit, the analog output to the DCS/PLC, distinguish between warning and dangerous contacts to ensure correct logic.

Power On Configuration: Confirm normal -24V DC power supply before powering on. Through panel buttons or remote configuration software, set valve position range, alarm threshold, delay, etc., and save for effect.

Sensor Installation: LVDT / potentiometer should be installed coaxially with the valve actuator, with the stroke range matching the module's range, and be firmly fixed to avoid vibration causing sensor displacement or cable wear.

Daily Maintenance

Inspection and Check: Regularly observe the LED light columns and indicator lights on the panel to confirm normal valve position display and no faults in the channels; check for any looseness, oxidation, or overheating at the connection terminals, and promptly address potential hazards.

Precision Calibration: Calibrate the module's measurement accuracy annually using a standard signal source (analog LVDT / potentiometer / 4-20mA signal) to ensure compliance with ±0.5% full range requirements.

Clean Cooling: Regularly clean the module surface and frame slots of dust to ensure good ventilation and cooling, and prevent dust-induced short circuits or poor cooling faults.

Replacement of Spare Parts: When replacing modules, sensors, or cables, must use the original Bentley product of the same model. Do not use non-original accessories to avoid compatibility issues or measurement errors.

IX. Usage Precautions

This module is not explosion-proof and has no built-in safety barrier. It is strictly prohibited to install and use it in flammable and explosive, areas with combustible gases or dust.

Sensor type must strictly match the module's input configuration. LVDT needs to confirm the excitation voltage and frequency, potentiometer needs to match the resistance range, 4-20mA needs to be correctly set for the input mode. Otherwise, it will cause measurement failure.

The stroke range of the valve must match the module's measurement range to avoid signal over-limitation due to insufficient stroke or reduced measurement accuracy due to excessive stroke.

Do not disassemble the module, modify the internal circuitry, or change the sensor wiring method privately. Illegal operations will cause equipment damage and loss of product warranty rights. Before conducting wiring, maintenance, or module replacement, the power supply of the machine frame must be cut off to prevent accidents such as short circuits and electric shock.

The alarm threshold should be set according to the process requirements of the unit. If it is too high or too low, it may lead to the failure of protection or frequent false alarms.

The installation position of the module should be as far away as possible from the frequency converter, transformer, high-voltage distribution cabinet and other strong electromagnetic interference sources to reduce the influence of external interference on the measurement signal.