The Foxboro SRD991 Intelligent Valve Positioner is a smart digital controller designed for precise valve actuation and reliable performance in process automation systems.
It converts the 4-20 mA input signal (with optional HART® communication) into accurate pneumatic output pressure to control single- or double-acting actuators.
Engineered by Foxboro (by Schneider Electric), the SRD991 offers advanced diagnostics, quick commissioning, and robust communication for demanding industrial environments.

High Accuracy & Stability — Continuous digital control ensures tight valve positioning and minimal hysteresis.
Smart Communication — Compatible with HART®, PROFIBUS-PA, and FOUNDATION™ Fieldbus protocols.
Auto-calibration Function — The device performs self-tuning for actuator and valve characteristics, reducing setup time.
Built-in Diagnostics — Monitors valve friction, air supply, and stem performance to predict maintenance needs.
Rugged Design — IP66/NEMA 4X aluminum housing suitable for harsh process environments.
Local Configuration — On-device LCD with four-button interface for local setup and status display.
Explosion-Proof Options — Available for hazardous areas (Ex ia, Ex d, CSA, ATEX, IECEx).
Wide Application Range — Supports rotary and linear actuators with customizable feedback modules.

The SRD991 stands out in the intelligent positioner market due to its modular design, multi-protocol communication, and high-resolution sensors.
It supports easy integration into existing control systems and allows continuous online diagnostics — enabling predictive maintenance and higher process uptime.

• Oil & Gas process control
• Chemical and petrochemical industries
• Power generation and steam systems
• Water and wastewater plants
• Paper, pulp, and refining industries
• OEM valve and actuator manufacturers

By continuously monitoring valve position and actuator pressure, the SRD991 dynamically adjusts output air to maintain accurate control.
The integrated diagnostics detect valve stiction or leakage early, reducing unscheduled downtime.
Its HART communication allows remote parameterization and online monitoring through standard asset-management tools.

At Dr. Industry Group, we provide:

• Original Foxboro SRD991 positioners – new, genuine, and fully tested
• Large inventory in stock for fast global shipment
• Technical configuration support for all communication protocols
• Worldwide export experience, especially to Southeast Asia, Middle East, and Central Asia
• One-stop valve automation solutions, including actuators, controllers, and accessories

Each SRD991 unit is carefully inspected and calibrated before delivery to ensure consistent performance.

Q1. What is the difference between SRD960 and SRD991?
The SRD991 is an advanced version with improved diagnostics, faster response, and wider protocol support (HART, PROFIBUS-PA, FOUNDATION Fieldbus).

Q2. Can SRD991 be used with double-acting actuators?
Yes, it supports both single- and double-acting pneumatic actuators through configurable output stages.

Q3. How is configuration done?
Via local keypad and LCD or remotely using FDT/DTM-based software such as FoxCom or HART asset management tools.

Q4. What materials are available for housing?
Aluminum alloy (standard), stainless steel (optional) for corrosive environments.

Q5. Does it support valve diagnostics?
Yes, it continuously analyzes valve friction, travel deviation, and response characteristics for predictive maintenance.

Dr. Industry Group Co., Ltd.
Shanghai – China
Website: www.shgongboshi.com
Email: edwardzhao@gbsxj.com
Phone: +86-15000725058