Case Study: Enhancing Safety and Efficiency with SIL 2 Heat Tracing for Natural Gas Pipelines
Industry: Natural Gas Pipeline Distribution
Product: ONE SERIES FIELD SAFETY SYSTEM for Remote Heater Control
Challenge: Preventing Freezing in High-Pressure Natural Gas Pipelines
National Grid operates city gate stations responsible for delivering natural gas to commercial and residential customers. To maximize throughput in transmission pipelines, high-pressure gas exceeding 1,000 PSI is supplied. However, before delivery, this pressure must be reduced to less than 100 PSI using pressure-reducing valves and regulators.
One significant challenge in this process is the Joule-Thomson effect, which causes a temperature drop as gas expands through the pressure-reducing valves. When combined with cold ambient temperatures, this phenomenon can freeze pipeline assets, rendering them inoperable and potentially leading to overpressure conditions—a major safety hazard.
Recognizing this risk, National Grid identified the need to upgrade its heating system safety controls to meet new corporate standards with SIL-certified equipment, ensuring a reliable and failsafe solution.
Solution: One Series SIL 2 Safety System for Heating Control
To mitigate the risk of pipeline freezing, National Grid implemented the One Series Field Safety System—a Class I, Div. 1 safety-rated system designed for hazardous locations. This advanced system provides:
✅ Loop-Powered 4–20 mA Output for continuous monitoring
✅ High-Capacity Safety Relay for immediate response
✅ Embedded Programmable Logic for automatic control
✅ SIL 2 Certification for compliance with the latest safety standards
By integrating temperature sensing, control logic, and alarm notifications into one compact, hazardous-location enclosure, the One Series Safety System ensures automated and precise heater control for the pressure-reducing valve.
When temperatures drop below 40°F, the system immediately alerts remote “Gas Control” operations, signalling a potential freezing risk in the natural gas stream.
Key Benefits: Cost-Effective Safety & Compliance
The One Series Safety System replaces three separate components—a temperature transmitter, process temperature switch, and gauge—simplifying pipeline heating system design while enhancing safety and reliability.
🔹 3-in-1 Safety System – Combines multiple components into one field-mounted device
🔹 Cost-Effective Upgrade – Eliminates the need for additional wiring, interconnections, and host system modifications
🔹 Reduced Risk of Freezing – Ensures uninterrupted gas flow by maintaining optimal heating
🔹 Compliance with SIL 2 Standards – Enhances overall system integrity and regulatory compliance
As a result of this successful implementation, National Grid has now standardized the One Series Safety System for both new installations and modernization projects, ensuring consistent risk reduction in heating control circuits across its natural gas distribution network.
Optimize Your Pipeline Safety with Westech Industrial
At Westech Industrial, we provide industry-leading safety solutions for natural gas transmission and distribution. Our experts can help you select and implement the right SIL-certified technology for your operation.
📞 Call us at 1-800-912-9262 or visit the UEC SIL 2 product page to learn more about the One Series Safety System and how it can enhance your pipeline safety and efficiency.