Premium Foxboro Srd991/Srd998/Srd990 Intelligent Valve Positioner for Precision Control

• Customization: Available
• Brand: Foxboro
• Power: Pneumatic
• Model NO.: Foxboro Srd991
• Adjusted Form: Switching Type
• Working Type: Rotary
• Pressure: Medium Pressure
• Work Temperature: Normal Temperature
• Acting Type: Double Acting
• Material: Aluminum
• Customized: Customized
• Structure: Rack and Pinion
• Item Name: Foxboro Srd991 Intelligent Positioner
• Model: Srd991
• Type Name: Intelligent Positioner
• Manufacturer: Foxboro
• Condition: New & Original in Factory Packing
• Factory Warranty: 12 Months
• Shipping Weight: 5 Kg
• MOQ: 1PC
• Communication: Hart, Foundation Fieldbus H1, Profibus-PA
• Input: 4 to 20 Ma
• Protection: Class IP 66 and NEMA 4X
• Explosion Protection: Intrinsic Safety According to ATEX / Iecex, FM
• Acting: Single or Double-Acting
• Supply Air Press: up to 7 Bar (105 Psig)
• Warranty: 1 Year
• Transport Package: Carton Boxes
• Specification: 30*30*30
• Trademark: Foxboro
• Origin: Germany
• HS Code: 9026900000
• Production Capacity: 100/Month
• Package Size: 30.00cm * 30.00cm * 30.00cm
• Package Gross Weight: 5.000kg

Product Description

Product Description

Foxboro SRD991 Valve Positioner Product Introduction
1. Overview
The Foxboro SRD991 Smart Valve Positioner is a high-performance digital valve controller designed for precise control of pneumatic control valves in industrial automation applications. Manufactured by Foxboro, the SRD991 is widely used in industries such as oil & gas, petrochemical, power generation, water treatment, and process manufacturing.
This advanced positioner offers high accuracy, reliability, and diagnostic capabilities, making it an essential component for modern control systems. It supports HART, Foundation Fieldbus, and PROFIBUS PA communication protocols, ensuring seamless integration with distributed control systems (DCS) and asset management software.

Detailed Photos

2. Key Features & Benefits
2.1 High Precision & Control Performance
High-resolution feedback ensures precise valve positioning (up to 0.1% accuracy).
Adaptive control algorithm automatically adjusts for changes in valve friction, pressure, and load variations.
Fast response time minimizes process variability and improves loop performance.
2.2 Advanced Diagnostics & Predictive Maintenance
Built-in self-diagnostics detects issues such as air supply problems, actuator leaks, and mechanical wear.
Valve signature analysis helps identify sticking, hysteresis, and other valve conditions.
Real-time monitoring of key parameters (position, pressure, temperature) via digital communication.
2.3 Robust & Reliable Design
Weatherproof & explosion-proof (ATEX, IECEx, FM
certifications available).
Wide operating temperature range (-40°C to +85°C / -40°F to +185°F).
Stainless steel housing for corrosion resistance in harsh environments.
2.4 Easy Configuration & Commissioning
Auto-calibration feature simplifies setup and reduces commissioning time.
Local user interface (LUI) with intuitive menu navigation.
HART communicator or DCS integration for remote configuration.
2.5 Communication & Integration
Supports HART 7, Foundation Fieldbus, and PROFIBUS PA protocols.
Digital signal transmission reduces wiring complexity and improves signal integrity.
Compatible with Foxboro Evo™ DCS and third-party control systems.

Product Parameters

Parameter	Specification
Input Signal	4-20 mA (HART), Fieldbus, PROFIBUS PA
Supply Pressure	1.4 to 7 bar (20 to 100 psi)
Air Consumption	< 0.05 Nm³/h (at steady state)
Accuracy	±0.5% of span (standard), ±0.1% (optional)
Repeatability	±0.1% of span
Ambient Temperature	-40°C to +85°C (-40°F to +185°F)
Enclosure Rating	IP66, NEMA 4X
Hazardous Area Approval	ATEX, IECEx, FM, CClass I, Div. 1 & 2
Mounting	Direct or bracket mounting (ISO 5211)
Materials	Stainless steel, aluminum, and engineered plastics

4. Applications
The Foxboro SRD991 is suitable for a wide range of industrial applications, including:
Oil & Gas: Control valves in refineries, pipelines, and offshore platforms.
Petrochemical: Precise flow control in chemical processing plants.
Power Generation: Steam turbine bypass, feedwater control.
Water & Wastewater: Flow regulation in treatment plants.
Pharmaceutical & Food: Hygienic process control.
5. Advantages Over Conventional Positioners

Feature	Conventional Positioner	Foxboro SRD991
Accuracy	±1-2% of span	±0.1-0.5% of span
Diagnostics	Limited or none	Advanced diagnostics & predictive maintenance
Communication	Analog only	HART, Fieldbus, PROFIBUS PA
Setup & Calibration	Manual adjustment	Auto-calibration & adaptive tuning
Maintenance	Reactive (failures detected late)	Predictive (early fault detection)

6. Installation & Commissioning
6.1 Mounting Options
Direct mounting on rotary or linear actuators (ISO 5211 compliant).
Bracket mounting for older valve models.
6.2 Wiring & Air Supply
Electrical connections: 2-wire (4-20 mA with HART) or digital bus wiring.
Pneumatic connections: 1/4" NPT or metric threads.
6.3 Configuration Steps
Mount the positioner on the valve actuator.
Connect air supply (1.4 to 7 bar).
Wire the electrical signal (HART or Fieldbus).
Perform auto-calibration via the local interface or HART communicator.
Verify operation with step-response tests.
7. Maintenance & Troubleshooting
7.1 Routine Maintenance
Inspect air supply for moisture or contamination.
Check mechanical linkages for wear or misalignment.
Monitor diagnostic alerts for early fault detection.
7.2 Common Issues & Solutions

Issue	Possible Cause	Solution
Valve not moving	Air supply failure	Check pressure & filter regulator
Erratic positioning	Loose linkage	Tighten mechanical connections
Communication failure	Wiring issue	Verify HART/Fieldbus connections
High hysteresis	Mechanical wear	Perform valve signature test

8. Conclusion
The Foxboro SRD991 Smart Valve Positioner is a state-of-the-art solution for industrial valve control, offering high precision, advanced diagnostics, and seamless integration with modern control systems. Its robust design, adaptive tuning, and predictive maintenance capabilities make it an ideal choice for critical process applications.

Company Profile

KeRui (weifang) Automation Equipment Co., Ltd. specializes in industrial automation instrument development, production and sales,technical services, and supporting equipment supply of specialized companies. The main products are flow meters, level meters,temperature meters, pressure meters, electrical meters, thermal intelligent meters, programmable controllers (PLC), DCS distributed control systems, and eight series of more than 1,000 specifications. Its products and technologies are widely used in electric power, metallurgy, petrochemicals, environmental protection, plastics, food, printing, tobacco, textile, dyeing, and other fields.
 

Packaging & Shipping

The packaging and transportation of instrumentation in global trade hinges on a synergy of advanced materials, rigorous testing, regulatory compliance, and smart logistics. By adopting hybrid structural designs, leveraging real-time monitoring technologies, and prioritizing sustainability, exporters can ensure the safe, efficient, and cost-effective delivery of precision instruments. Continuous innovation in materials science and IoT integration will further redefine industry standards, enhancing resilience in an increasingly interconnected market.

FAQ

Q: How long will you give me the reply?
A: We will reply to you as soon as we see the information.
Q: What is the delivery time?
A: Our delivery time is within 3-7 days after we get your payment;
for large qty mass orders, the time should be confirmed again for you.
Q: How about your package?
A: Do not worry about the package, we have rich experience in packing, and all our package is wooden case package.
Q: How about the payment terms?
A: You can choose T/T.
Q: Do you provide samples?
A: Yes, we have materials in stock to help you to get the samples as soon as we can.
Q: What is the MOQ?
A:1PC.
Q: Can I get a lower price if I order large quantities?
A: Yes, cheaper prices with more bigger size orders.