Current Support Status
Emerson currently maintains a Support and Maintenance phase for the 4320 installed base. You cannot buy new units, but you can keep existing ones running:
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Spare Parts Availability: Most mechanical components, mounting brackets, and housing parts are still available through authorized channels.
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Power Modules: Replacement SmartPower™ lithium battery modules are actively stocked to ensure your wireless mesh remains powered.
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Technical Support: Access to technical documentation, calibration procedures, and troubleshooting assistance remains active for field technicians.
Core Technical Advantages (Legacy Features)
The 4320 earned its reputation by solving the “last mile” connectivity problem in dense process environments.
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Linkage-less Feedback: It utilized non-contact, Hall-effect sensing technology. By removing the physical linkage between the valve stem and the monitor, it eliminated the #1 cause of mechanical wear and measurement drift.
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WirelessHART Reliability: Operating on the 2.4 GHz self-healing mesh network (IEC 62591), it achieved 99.9% reliability even in high-interference areas where traditional Wi-Fi often fails.
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Universal Retrofitting: The 4320 was designed to mount on almost any linear or rotary valve — including non-Emerson brands — making it a “swiss army knife” for digital transformation projects.
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SmartPower™ Efficiency: Depending on the user-selected update rate, the power modules were engineered to last up to 10 years, drastically reducing the frequency of hazardous-area maintenance.
Technical Core
| Category | Specification / Detail |
| Communication Protocol | WirelessHART (IEC 62591) |
| Input Range | Linear: 2 to 24 in (50 to 600 mm); Rotary: 0 to 180 degrees |
| Power Source | Replaceable SmartPower™ Lithium Battery Module |
| Update Rate | User-selectable from 1 second to 1 hour |
| Housing Material | Low-copper aluminum or Stainless Steel (NEMA 4X / IP66) |
| Hazardous Area | Intrinsically Safe (IS) and Explosion-proof options |
| Operating Temp | -40 to 85°C (-40 to 185°F) |
Modern Alternatives & Migration
If you are expanding your wireless network or have a 4320 that has suffered a catastrophic failure, the current industry standards for replacement are:
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Fisher TopWorx™ Wireless Series: The primary successor for discrete valve position monitoring.
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Rosemount™ 702 Wireless Discrete Transmitter: Often used for simpler on/off feedback applications.
Xi’an Yunrui Trading Co., Ltd. Technical Support
Xi’an Yunrui Trading Co., Ltd. continues to support clients who rely on the Fisher 4320 infrastructure. While we cannot provide new complete units, we specialize in sourcing original spare parts and high-capacity power modules to ensure your plant stays digital. Our engineering team can also assist in mapping out a migration path to TopWorx™ or Rosemount™ alternatives to ensure your WirelessHART gateway settings remain compatible.
If you need to verify the remaining life of your 4320 power modules or require a quote for legacy spare parts, please contact our technical team.
