Pipeline Industry Gas Detection Solutions: Nexisense Ensures Pipeline Safety and Efficient Operation

The pipeline network is the lifeline for energy, chemical, and urban gas industries, including long-distance natural gas pipelines, coal gas extraction systems, petroleum crude/fuel oil pipelines, and hydrocarbon emission lines. These pipelines often transport flammable and explosive media (e.g., methane, propane, ethylene) or toxic and hazardous gases (e.g., H₂S, CO, SO₂). Any leak may trigger explosions, fires, poisoning incidents, environmental pollution, and economic losses.

Although petroleum pipelines primarily transport liquids, volatile components in crude oil (e.g., benzene, toluene, light hydrocarbons) and associated gases can easily escape at normal temperatures, forming explosive atmospheres. Corrosion, aging joints, and third-party damage further increase risks. National standards (e.g., GB 50251 "Design Code for Gas Transmission Pipelines", AQ 3053 "Technical Specifications for Pipeline Leak Detection") mandate that high-risk pipeline sections must have fixed gas detection systems for real-time monitoring and early warning.

Nexisense focuses on industrial gas safety and provides online detection solutions adaptable to various sampling methods, helping companies build a reliable safety network at critical nodes such as valve rooms, compressor stations, pump stations, and pipeline crossings.

Pipeline Gas Risk Characteristics and Monitoring Requirements

Pipeline gas monitoring faces unique challenges:

• Variety of media: Natural gas mainly CH₄, petroleum associated H₂S/light hydrocarbons, coal gas high CH₄+CO₂ concentration.

• Leak types: Minor seepage accumulating gradually or sudden rupture releasing large amounts instantly.

• Complex environments: buried/overhead pipelines, remote locations, high/low pressure, corrosive conditions.

• Response requirements: fast detection (<10s), low false alarms, interference resistance.

Effective monitoring can trigger alerts before concentrations reach the lower explosive limit (LEL) or occupational exposure limit, enabling ventilation, valve shutoff, or remote isolation to reduce accident probability.

How to Choose Pipeline-Specific Gas Detection Equipment

Selection should consider sampling method and application scenario:

• Diffusion-type: monitors external leaks, installed near valves or joints to capture ambient gas.

• Pipeline-type: threaded directly into pipeline sampling port, suitable for normal temperature/pressure monitoring.

• Pump-suction/flow-through type: draws sample through pump, suitable for high/low pressure, high flow, or long-distance sampling.

• Other factors: explosion-proof level (Ex d IIC T6 Gb), sensor principle (catalytic combustion/infrared/electrochemical), output (4-20mA/RS485 Modbus RTU), customized range/units.

  
  

Nexisense Core Product Introduction

Online Fixed Gas Detector – SGA-500 Series

The SGA-500 series uses imported sensors with patented algorithms (32-bit microprocessor + 24-bit ADC full-range temperature and humidity compensation), factory-calibrated, ensuring high accuracy and stability.

24V power, plug-and-play, supports diffusion, pipeline, and pump-suction sampling. Real-time concentration display, automatic alarm + relay output.

• Modular design, customizable sensors, ranges, alarm points, OEM appearance.

• Suitable for common pipeline gases: CH₄, C₃H₈, H₂S, CO.

• Explosion-proof housing, IP65+, suitable for outdoor and indoor pipe corridors.

System Integration and Linkage

Combined with the SGA-800 alarm controller, enables multi-point centralized display, unified power supply, and historical storage. Supports RS485 Modbus RTU or 4-20mA output, seamlessly interfacing with PLC/DCS/SCADA for closed-loop control: leak → automatic ventilation + remote valve shutdown.

Pump-suction configuration includes vacuum pump + filter, suitable for high-pressure pipeline sampling; pipeline-type uses M45×1.5 threaded installation for quick connection.

Sampling Methods and Installation Guidelines

• Diffusion: install 30-60cm near leak sources (flanges, valves), heavy gases below, light gases above.

• Pipeline-type: drill M45×1.5 hole, thread in gas cup, suitable for normal temperature/pressure.

• Pump-suction: connect hose or heated line, suitable for high/low pressure or long distance.

• Note: use shielded cables to prevent interference; regularly check filters and seals; outdoor installations require sun/rain protection.

  
  

Typical Applications

• Long-distance natural gas pipelines: CH₄/H₂S monitoring at valve rooms and stations, covering explosion-proof areas.

• Petroleum pipelines: monitor volatile hydrocarbons and H₂S at pump stations and storage areas.

• Coal gas extraction systems: high-concentration CH₄ monitoring, linkage with gas extraction.

• Chemical hydrocarbon emission lines: VOC/light hydrocarbon leak early warning.

Frequently Asked Questions (FAQ)

1. What sampling methods does the SGA-500 series support in pipelines, and how to choose?
Supports diffusion (external leaks), pipeline (M45×1.5 threaded direct insertion, normal temperature/pressure), and pump-suction (sample extraction, high/low pressure, long distance). Diffusion for valve-area leaks, pipeline-type for direct internal sampling, pump-suction for high flow or filtered scenarios.

2. Explosion-proof level and applicable zones?
Ex d IIC T6 Gb certified, suitable for Zone 1/Zone 2 explosive gas areas, widely used in natural gas/petroleum pipeline explosion-proof zones. Housing is corrosion and impact resistant, suitable for buried or overhead outdoor pipelines.

3. How to interface with PLC/DCS? Supported protocols?
Supports 4-20mA (2/3-wire) and RS485 Modbus RTU, compatible with major PLC/DCS. Controller optional Modbus TCP for remote monitoring, data upload, and linkage control.

4. Sensor life and calibration cycle? Maintenance?
Catalytic sensors: 3-5 years; IR/electrochemical: 2-4 years (depending on gas). Built-in life prediction, calibrate zero+span every 6-12 months (standard gas). Pump-suction requires periodic filter replacement; self-diagnosis reduces on-site maintenance.

5. Pipeline-type installation steps and precautions?
Drill M45×1.5 hole at proper location, clean threads, insert gas cup, ensure seal. Select stable flow, avoid liquid accumulation, use shielded cables, avoid high-heat sources.

6. How to handle high/low pressure pipelines with pump-suction sampling?
Pump-suction has built-in vacuum pump with adjustable rate, adapts to positive/negative pressure. Heated line prevents condensation; filter prevents clogging; extended hoses maintain fresh sample delivery.

7. Multi-level alarm and automatic linkage possible?
Yes, supports multiple thresholds (pre-alarm/alarm/high-high alarm), each with independent output: level 1 ventilation, level 2 valve shutoff, level 3 pump cutoff. Controller with multiple relays for zoned logic.

8. How to get custom solutions, manuals, or project cases? Response time?
Submit pipeline media, pressure, temperature, point numbers; team responds within 24h. Provides selection manuals, explosion-proof certificates, installation diagrams, project cases, 3D models. Standard products: 1-3 working days; custom: 5-10 working days.

Conclusion: Nexisense Protects Every Meter of Pipeline Safety

Pipeline safety is critical for energy supply and social stability. Nexisense, with flexible sampling methods, high-reliability sensors, and system integration, provides precise, stable gas monitoring for natural gas, petroleum, and coal gas pipelines. Whether new construction or upgrades, leakage risks are effectively controlled.

If your pipeline project requires gas detection upgrades, contact the Nexisense team for tailored solutions, on-site surveys, and technical support. Pipeline efficiency begins with safety monitoring.