Schneider SRI986-BIDS7EBBNA

Shared Core Technical Specifications

• Input Control Signal: Standard 4–20mA DC analog signal; input resistance <200Ω at 20°C ambient temperature
• Supply Air Pressure Range: 1.4bar–6bar clean dry instrument air
• Air Quality Standard: ISO8573-1 particle class 2, oil content class 3; filter regulator mandatory upstream
• Output Pneumatic Signal: Proportional air pressure 0–100% of supply air pressure to actuator diaphragm
• Linear Stroke Adaptation: Linear actuator stroke 8mm–100mm adjustable
• Rotary Angle Adaptation: Linear rotary range 30°–120°, equal percentage 90° rotary valve support
• Ambient Operating Temperature: -40°C to +80°C wide temperature range
• Compliance Standard: IEC 534-6 NAMUR standard actuator mounting interface

Differentiated Model Configuration Breakdown

Model SRI986-BIDS7EBBNA

1. Built-in dual mechanical limit switch feedback contacts for full open/full closed valve position hard signal output
2. Integrated 4–20mA valve position transmitter to upload actual stroke value back to control system
3. Standard NAMUR manifold connection base plate included for direct actuator mounting
4. No ATEX intrinsically safe explosion-proof certification, for non-hazardous general industrial areas

Model SRI986-BIDS7ZZZNA

1. No built-in limit switch module, no integrated position feedback transmitter
2. Without integrated mounting manifold base plate; customer separately purchase NAMUR mounting accessories
3. No explosion protection rating, simplified basic control version for low-cost standard valve control applications
4. Single acting pneumatic output only, direct action signal response characteristic

Shared Core Function Features

1. Independent Zero & Span Calibration: Separate adjustment potentiometers for zero offset and full stroke span without mutual interference during on-site calibration
2. Adjustable Amplification & Damping Parameters: Tunable response gain and signal damping to eliminate valve stroke oscillation under high loop gain control conditions
3. Split Range Control Support: Up to 3 times signal split range function for two-position sequential valve control with single 4–20mA input signal
4. Low Vibration Immunity Design: Internal pneumatic amplifier mechanical structure optimized to resist vibration from pipeline fluid flow and pump equipment
5. Modular Expandable Structure: Optional booster relay, external limit switch and explosion-proof housing can be retrofitted on basic unit
6. Direct/Reverse Action Switchable: Internal jumper to switch between direct (signal increase = valve open) and reverse (signal increase = valve close) control behavior

Shared Application Scenarios

• Petrochemical refining pipeline control valves (linear globe valve, rotary ball valve)
• Natural gas transmission pressure regulating valves
• Power plant boiler steam feedwater control valves
• Food & beverage process sanitary pneumatic actuated control valves
• Water treatment chemical dosing proportional control valves
• Pharmaceutical factory sterile process fluid regulating valves

Shared Material Composition & Structural Characteristics

• Outer Enclosure Housing: High-impact chemical resistant ABS plastic shell with UV anti-aging coating
• Internal Pneumatic Amplifier Unit: Stainless steel precision spool valve assembly with PTFE low-friction sealing gaskets
• Position Sensing Mechanism: Stainless steel feedback lever with wear-resistant ceramic contact points
• Pneumatic Connection Ports: Brass nickel-plated air supply/output threaded ports (1/4” NPT standard thread)
• Protection Grade: IP65 full housing dust and water splash resistance

Shared Working Principle

1. 4–20mA electrical control signal enters electromagnetic torque motor inside positioner, generates proportional magnetic torque corresponding to input current magnitude
2. Magnetic torque drives feedback lever and baffle nozzle pneumatic amplification circuit, changes nozzle back pressure
3. Back pressure signal controls internal pneumatic spool valve to adjust air supply flow into actuator diaphragm chamber
4. Valve actuator stroke mechanical feedback lever reversely balances magnetic torque to form closed-loop positioning system; stable stroke position achieved when torque balance condition met
5. EBBNA variant additional position sensor converts mechanical stroke into 4–20mA feedback signal for remote valve position monitoring

Shared Installation Requirements

1. Mount directly on top of pneumatic actuator via standard NAMUR mounting bracket; feedback lever connected tightly to valve stem without mechanical clearance
2. Install precision air filter pressure regulator upstream of positioner supply air port to stabilize instrument air pressure within 3–4bar nominal operating pressure
3. Pneumatic pipeline use 6mm copper or PTFE instrument air tubing; tubing bending radius minimum 10mm without sharp folding
4. Mount positioner vertically to avoid gravity interference on internal mechanical feedback lever balance
5. Ambient installation environment must avoid direct contact with corrosive acid, alkali liquid and steam splash

Shared Usage Precautions

1. Perform zero and span re-calibration after valve maintenance, actuator diaphragm replacement or positioner disassembly
2. Drain water condensate from instrument air filter regulator drain valve daily to prevent water entering internal pneumatic spool and causing sticking
3. Do not supply air pressure exceeding maximum 6bar rated limit; overpressure damages internal plastic sealing components
4. Regularly clean nozzle and baffle assembly every 6 months in dusty industrial environments to eliminate pneumatic amplifier blockage
5. For SRI986-BIDS7EBBNA model, avoid overloading built-in limit switch contact current above 5A resistive load rating