Fisher DVC2000

Description

Technical Specifications

1. Electrical Signal Parameters

• Standard Analog Input Signal: 4–20 mA DC (split-range configurable)
• Minimum Operating Loop Voltage: 8.5 V DC (local LCD operation); 9.0 V DC (HART communication)
• Maximum Input Terminal Voltage: 30 V DC
• Reverse Polarity Protection: Built-in, no hardware damage under reverse wiring
• Overcurrent Protection: Input circuit current limiting self-protection
• Communication Protocol: HART 5 / HART 7 digital superimposed communication

2. Pneumatic Performance

• Supply Air Pressure Operating Range: 1.5–7 bar (22–101 psig)
• Minimum Control Span: 0.5 bar (7 psig)
• Maximum Control Span: 7 bar (101 psig)
• Air Consumption (Static): 0.06 Nm³/h @1.5 bar supply; 0.12 Nm³/h @4 bar supply
• Supported Actuator Travel: Linear stroke ≤50 mm (2 inch); 90° quarter-turn rotary actuator
• Single-acting standard output; double-acting operation requires external pneumatic reversing relay

3. Environmental & Temperature

• Operating Temperature Range: -40°C to +80°C (-40°F to 176°F); LCD display unreadable below -20°C
• Storage Temperature: -50°C to +90°C
• Protection Enclosure Grade: IP66, NEMA 4X

4. Mechanical Connection Standards

• Electrical Conduit Port: M20 internal thread / 1/2 NPT internal thread dual standard
• Pneumatic Air Port: G1/4 internal thread / 1/4 NPT internal thread dual standard
• Mounting Standard: IEC 60534-6-1, IEC 60534-6-2, VDI/VDE 3845, NAMUR

5. Hazardous Area Certifications

• Intrinsically Safe: CSA, FM, ATEX, IECEx, NEPSI, INMETRO, CUTR, PED, KGS, ANZEx
• Classification: Class I Division 1 / Zone 0, Ex ia IIC T6

Material Composition

• Main Enclosure: Die-cast low copper aluminum alloy, electrostatic anti-corrosion coating
• Internal Pneumatic Valve Components: Stainless steel + engineering PTFE sealing spool
• Feedback Stroke Rod: 316L stainless steel
• LCD Window: Impact-resistant tempered polycarbonate
• Internal Circuit Board Base: FR4 high-temperature flame retardant PCB
• Pneumatic Sealing Rings: Viton fluororubber (standard); EPDM optional for neutral media

Structural Features

• Two-stage pneumatic amplification internal structure, high response sensitivity to tiny input signal changes
• Linkage-free non-contact stroke feedback sensor, eliminates mechanical linkage wear failure
• Integrated local operation panel: Multi-language LCD screen + four physical push buttons
• Optional integrated I/O expansion module with two independent limit switches + stem position transmitter
• 3-point fixed mounting interface for direct installation on Fisher GX, 657, 667 series actuators without extra brackets
• Internal integrated air flow channel on actuator yoke leg, eliminates external air tubing for air-to-open configuration
• Cage clamp type wiring terminals, tool-free fast cable connection

Working Principle

1. Control system transmits 4–20 mA analog setpoint signal to positioner input terminal;
2. Internal microprocessor collects real-time valve stroke feedback signal from non-contact displacement sensor;
3. MCU compares setpoint stroke value with actual feedback stroke value, calculates deviation error;
4. Two-stage pneumatic amplifier adjusts output air pressure to pneumatic actuator diaphragm/cylinder to push valve stem movement;
5. Closed-loop real-time correction until actual stroke matches target setpoint;
6. HART bus superimposes digital diagnostic data on 4–20 mA analog loop, realizes remote reading of valve friction, dead band, air leakage and actuator health status.

Function Features

• Real-time closed-loop stroke control with high repeatability and linearity
• Full set of online valve diagnostic functions supported by ValveLink PC software
• Local on-site calibration, parameter setting and stroke adjustment without external handheld communicator
• 7-language built-in LCD interface (English, Chinese, German, French, Italian, Spanish, Japanese)
• Split-range signal configuration for dual-valve cascade control loops
• Built-in anti-vibration filtering algorithm for stable operation on high-vibration pipeline equipment
• Over-temperature, over-pressure, short-circuit automatic fault alarm output

Performance Advantages

1. Linkage-free feedback design reduces mechanical failure rate by 70% compared with traditional mechanical positioners;
2. Two-stage pneumatic structure achieves ultra-fast response time ≤150 ms for small signal changes;
3. Non-disruptive online diagnostic test without stopping production process;
4. Compact overall size adapts to narrow installation space of small control valves;
5. Full global explosion-proof certifications applicable to petroleum, chemical flammable hazardous working conditions;
6. Low static air consumption reduces plant compressed air operation cost.

Applicable Industries

Petroleum refining, natural gas transmission, chemical processing, power plant thermal control, pharmaceutical production, food & beverage manufacturing, water treatment, pulp & paper, HVAC industrial process control.

Installation Requirements

1. Mounting surface flatness meets VDI/VDE 3845 standard, mounting screw torque controlled at 8 N·m;
2. Compressed air supply must be filtered to Class 3 clean air standard (particle ≤5 μm, dew point ≤-40°C);
3. Electrical wiring must use shielded twisted pair cable, cable shielding single-end grounded at control cabinet side;
4. Pneumatic tubing connection must use PTFE sealing tape, avoid excessive thread winding blocking air passage;
5. Stroke feedback rod must maintain coaxial alignment with valve stem, maximum allowable offset ≤0.5 mm;
6. For explosion-proof zone installation, strictly follow national hazardous area wiring specification for conduit sealing.

Usage Precautions

• Forbid supply air containing oil, water or solid particles, internal pneumatic spool will jam and lose control function;
• Do not disassemble sealed main enclosure in hazardous explosion-proof zones; disassembly voids explosion-proof certification;
• Electrostatic discharge protection wristband must be worn when opening electrical terminal cover; static electricity triggers random valve stroke fluctuation;
• LCD display function fails continuously below -20°C ambient temperature; heat insulation protective cover required for low-temperature outdoor installation;
• Do not exceed 30 V DC loop input voltage, overvoltage burns internal main control circuit board;
• Regularly execute ValveLink diagnostic test every 3 months to detect early actuator packing friction wear.