Flowserve Logix 520MD Digital Valve Positioner
The Flowserve Logix 520MD is a two-wire digital valve positioner with HART communication, designed for precise control of single-acting pneumatic actuators on linear and rotary valves. It is powered by the 4-20 mA input signal and uses electronic control combined with a pneumatic output stage to position the valve accurately according to the command signal.
Product Overview
This positioner features simple local configuration and calibration options, including DIP switches and calibration buttons on related MD series units. It supports HART protocol for remote setup and monitoring. The design emphasizes reliable performance in industrial environments, with options for local status indicators and, in later versions, enhanced diagnostic capabilities. The Logix 520MD series has been widely applied for valve positioning where digital communication and consistent response are required. Note that the original Logix 520MD is primarily supported as an aftermarket product, with the updated 520MD+ representing the current generation offering improved features.
Technical Specifications
| Specification |
Details |
| Type |
Digital HART Positioner |
| Input Signal |
4-20 mA (two-wire) |
| Communication |
HART |
| Power |
Loop-powered from 4-20 mA signal |
| Minimum Operating Current |
Approximately 3.6–3.8 mA |
| Actuator Compatibility |
Single-acting (linear and rotary) |
| Air Supply Pressure |
Typically 1.5 to 6.0 bar (22 to 87 psi) for original series |
| Output Pressure |
0 to 100% of supply pressure |
| Housing / Protection |
Industrial design suitable for process environments |
| Hazardous Area Options |
Intrinsically Safe and Non-Incendive ratings available (series dependent) |
Application Industry
Used in process industries such as oil and gas, chemical processing, power generation, refining, and general industrial plants for accurate positioning of pneumatic control valves.
Common Problems
Users of conventional positioners may experience limited remote diagnostics, more involved calibration, or reduced insight into valve health. The Logix 520MD series addresses these through HART communication, local interface options, and diagnostic features that help monitor performance.
Replacement Models
The original Logix 520MD can be replaced or upgraded with the current Logix 520MD+ digital positioner, which offers enhanced diagnostics, piezo technology, and broader communication support while maintaining similar mounting and application compatibility.
Why Buy From Us
We supply genuine Flowserve Logix positioners and related aftermarket support, with practical assistance for matching the correct configuration to your valve and process requirements.
Stock & Delivery Time
Typical production and delivery time is 6-8 weeks (subject to availability for aftermarket or current-generation units).
RFQ Form
Please provide details on actuator type, mounting preference, required communication or diagnostic level, hazardous area needs, and quantity for a tailored quotation.
