Flowserve Logix 520MD Smart Digital Positioner with ASCO Solenoid Valve HART Pneumatic Control

The Flowserve Logix™ 520MD+ is a two-wire, 4-20 mA digital valve positioner that uses the HART protocol for bidirectional communication. It is a fully electronic and pneumatic closed-loop instrument designed for precise stem-position control of single- or double-acting linear and rotary actuators. The positioner is powered solely by the 4-20 mA loop (minimum start-up current 3.8 mA) and incorporates an inner-loop (pilot-relay) and outer-loop (stem-position) control algorithm. Local configuration is possible via DIP switches, buttons and optional LCD; advanced diagnostics and configuration are performed with ValveSight DTM software or a HART handheld communicator.

• Dual-loop control with automatic inner-loop offset optimization during stroke calibration
• HART 5/6/7 protocol support with burst-mode capability
• Configurable characterization (Linear, Equal Percent, Custom 21-point) plus Soft Limits and Tight Shut-off
• Optional Multi-Function Card (AO 4-20 mA, Discrete Output, Discrete Input)
• Optional limit switches (mechanical, reed or inductive NAMUR) and remote-mount feedback
• ValveSight diagnostic levels (Standard / Advanced / Pro)
• Local user interface with status LEDs and optional LCD
• Intrinsically safe, Type n and Type t certifications (ATEX, IECEx, cFMus)

Precise positioning of control valves in oil & gas, refining, chemical, power generation and general process industries where HART diagnostics, hazardous-area certification and high-resolution control are required.

• Does the 520MD+ require external power? No – it is loop-powered.
• Can it be used on natural gas? Yes, with sweet natural gas and proper venting of exhaust ports.
• How is stroke calibration performed? Press and hold the QUICK-CAL button for 3–4 seconds after setting DIP switches.
• What is the difference between 520MD+ and 510+? The 520MD+ includes HART communication; the 510+ does not.

• Phone/WeChat/WhatsApp: +8613916209596
• Email: svetama@gbsxj.com

• Logix 510+ (non-HART)
• ValveSight DTM software
• Multi-Function Card
• limit-switch boards
• remote-mount kits
• mounting kits for Mark One / FlowTop / Valtek / MaxFlo / NAMUR actuators
• spare-part kits and gage blocks.