Xi'an Runlai RL-E100Ex Explosion-proof Oxygen Analyzer Application Case at Petrochemical Terminal

I. Operational Background: XX Petrochemical Terminal is a dedicated loading and unloading berth for refined oil and crude oil, equipped with an onshore-offshore interface oil and gas recovery system. It handles the loading and unloading of tankers, the sealed collection of oil and gas, and the harmless treatment of VOCs. The terminal is located in Zone 1, a highly flammable and explosive hazardous area. Key pain points and compliance requirements at the site

Explosion-proof necessity: Loading and unloading operations release large amounts of gasoline and diesel fumes. When these fumes mix with air, an explosive mixture can easily form if the oxygen content exceeds 8%. Static electricity or sparks from equipment can trigger combustion and explosion accidents. Dock regulations require real-time online oxygen measurement at the inlet and outlet of oil and gas pipelines, along with interlock protection for exceeding limits.

Harsh environmental interference: Docks are located near the sea with high humidity and large temperature differences between day and night, ranging from -10°C to 45°C. Oil and gas fumes contain water vapor and trace amounts of corrosive sulfur compounds, which can cause ordinary analyzers to drift and sensors to degrade rapidly, leading to frequent false alarms.

National mandatory compliance standards: According to JT/T 1333-2020 "Oil and Gas Recovery Ship-Shore Equipment" and GB/T 50759-2022 "Oil and Gas Recovery Facilities Specifications," explosion-proof oxygen analyzers must be installed at the inlet and outlet of oil and gas recovery systems. Monitoring data must be integrated into the dock's DCS control system to trigger audible and visual alarms when oxygen levels exceed limits, automatically shut off oil and gas delivery valves, and implement automatic nitrogen inerting interlock logic.

Shortcomings of old equipment: Previously, traditional oxygen analyzers were used at the dock without complete explosion-proof certification. They had severe zero-point and range drift, requiring multiple on-site calibrations each month. They also had slow response times and could not trigger interlocks promptly in case of sudden changes in oxygen concentration, posing significant control risks.

To completely address these three major challenges—monitoring, compliance, and stable operation—XX Petrochemical Dock selected the Xi'an Runlai RL-E100Ex explosion-proof oxygen analysis system. These systems were installed on the inlet and outlet main pipelines of the oil and gas recovery ship-shore equipment, enabling continuous online oxygen monitoring throughout the entire process.

10°C to 45°C, with oil and gas containing water vapor and trace amounts of corrosive sulfur compounds. Conventional analyzers are prone to drift, sensors degrade rapidly, and false alarms occur frequently.

National mandatory compliance standards: According to JT/T 1333-2020 "Terminal Oil and Gas Recovery Ship-Shore Equipment" and GB/T 50759-2022 "Oil and Gas Recovery Facilities Specifications," explosion-proof oxygen analyzers must be installed at both the inlet and outlet of oil and gas recovery systems. Monitoring data must be integrated into the terminal's DCS control system to achieve audible and visual alarms for oxygen content exceeding limits, automatic shutdown of oil and gas transfer valves, and nitrogen inerting automatic replacement interlock logic.

Shortcomings of old equipment: The terminal previously used traditional oxygen analyzers without complete explosion-proof certification, experiencing severe zero-point and span drift. Multiple on-site calibrations were required monthly, with slow response times and an inability to trigger interlocks promptly during sudden changes in oxygen concentration, posing significant control vulnerabilities.

To thoroughly address the three major challenges of monitoring, compliance, and stable operation, XX Petrochemical Terminal selected the Xi'an Runlai RL-E100Ex explosion-proof oxygen analysis system, which was installed on the inlet and outlet main pipelines of the oil and gas recovery ship-shore equipment, enabling continuous online oxygen content monitoring throughout the entire process.

User Evaluation (Equipment Management Department of XX Petrochemical Terminal) Since the RL-E100Ex explosion-proof oxygen analyzer was put into operation at the terminal's oil and gas recovery facility 18 months ago, the equipment has been running continuously and stably throughout the entire period. The terminal's equipment and management department have made the following comprehensive evaluations:

• Significant improvement in control capability: The equipment's explosion-proof rating fully meets the requirements of Zone 1 hazardous areas at the terminal. It has a fast response time, and in scenarios where oxygen concentration fluctuates abnormally during tanker loading/unloading and pipeline maintenance, it can issue audible and visual alarms in a timely manner and trigger interlocks. This has completely eliminated the risks associated with the old equipment's lagging response and false alarms. There have been no incidents of excessive oil, gas, or oxygen content throughout the year.
• Strong operational stability and significantly reduced maintenance costs: In the terminal's harsh environment, characterized by high humidity near the sea and impurities in the oil and gas, the instrument's zero point and range have shown almost no drift. Originally requiring 2-3 on-site calibrations per month, now only a simple quarterly check is needed. The pre-treatment unit's filtration effect is excellent, and the sensors have not experienced any corrosion or wear. The core sensors have not needed to be replaced in 18 months, resulting in a 70% reduction in the cost of instrument maintenance labor and spare parts procurement.
• Equipment meets terminal control and compliance requirements: The device's dual-signal output of 4-20mA and RS485 allows for direct connection to the terminal's DCS system. Oxygen content data is stored and traceable in real-time, fully meeting the on-site inspection standards for oil and gas recovery facilities set by transportation, environmental protection, and emergency management departments. No additional modifications are required to pass annual or special environmental inspections.