Emerson TVA-M2WGNCM TopWorx TVA Series Valve Position Monitor Switch Box

Basic Overview

Model Code Breakdown

• TVA: Compact composite housing T-series valve position monitor
• M2: 2pcs mechanical SPDT limit switches
• W: Standard visual position indicator dome
• G: Green OPEN / Red CLOSED 90° visual window
• N: NAMUR standard shaft interface for direct valve actuator mounting
• CM: Composite resin housing, silicone O-ring seals

Core Technical Specifications

1. Switch Configuration

• 2 independent mechanical SPDT mechanical microswitches
• Used to transmit valve fully open / fully closed digital feedback signals to PLC/DCS
• Standard low-voltage dry contact signal, compatible with 24VDC control circuits

2. Mounting & Mechanical

• Shaft: 304 stainless steel NAMUR standard rotary shaft, direct mount to quarter-turn pneumatic actuator
• No built-in solenoid valve, no manual override function
• Housing: High-strength composite resin lightweight enclosure
• Sealing: Silicone O-rings for dust and moisture resistance
• Weight: Approx 0.51 kg

3. Wiring & Conduit

• Two 1/2" NPT resin conduit ports for cable entry
• Internal screw terminal wiring for switch signal cables
• Transparent dome cover for on-site visual valve status check without opening housing

4. Visual Indication

• 90° wide viewing window: Green mark = Valve OPEN, Red mark = Valve CLOSED
• Rotatable indicator dome supports normal/reverse valve action setup

5. Environmental & Protection

• Designed for non-hazardous general industrial areas (no explosion-proof certification)
• Operating temperature range: -30°C ~ +70°C
• Protection class: NEMA 4 equivalent, dustproof and splash-proof for indoor workshop

Key Advantages

1. NAMUR direct mounting design, simple installation on ball valve, butterfly valve pneumatic actuators
2. Dual mechanical switch independent feedback, reliable valve position signal collection
3. Transparent visual dome, field staff can quickly judge valve open/closed state
4. Lightweight composite housing, corrosion-resistant, low maintenance
5. Modular cam adjustment, easy calibration of switch trigger position
6. Compact flat structure, occupies minimal space on valve top

Main Functions

1. Detect rotary valve full open / full closed mechanical position
2. Output switch dry contact signals to PLC, DCS or local alarm lights
3. On-site visual status display for valve operation inspection
4. Provide interlock feedback for process control loop safety logic

Typical Application Scenarios

• Water treatment & sewage pipeline ball/butterfly valves
• HVAC heating ventilation air conditioning control valves
• General factory non-explosion risk fluid process pipelines
• Packaging, food machinery fluid cut-off valves
• Centralized plant DCS valve remote monitoring system