H₂S Measurement in Natural Gas Pipelines

Continuous Hydrogen Sulfide Monitoring for Pipeline Gas Quality — H2S-625

Hydrogen sulfide is both toxic and corrosive, and pipeline gas quality specifications typically limit H2S to only a few parts per million, commonly around 4 ppm or a fraction of a grain per 100 standard cubic feet. Gas entering the pipeline from sour wells or third-party sources must be checked continuously to confirm it meets this specification before custody transfer.

The H2S-625 continuous analyzer gives pipeline operators dependable, low-maintenance H2S monitoring at receipt points, compressor stations, and interconnects, supporting both safety and gas quality compliance.

Why H₂S Monitoring Matters

Beyond its acute toxicity to personnel, hydrogen sulfide reacts with pipeline steel to accelerate sulfide stress cracking and general corrosion, shortening infrastructure life. Because pipeline quality specifications set firm H2S limits for custody transfer, continuous monitoring at receipt and interconnect points is essential both to protect workers and to enforce contractual gas quality terms.

Where It's Used

Gas receipt and custody transfer points — confirming sour gas is treated before entering the pipeline
Compressor stations — protecting equipment and personnel from H2S exposure
Underground storage facilities — verifying withdrawal gas quality
Interstate pipeline interconnects — checking gas quality across ownership boundaries

Recommended Analyzer

H2S-625 Continuous H₂S Process Analyzer

The H2S-625 is a continuous online analyzer built to deliver stable, low-ppm hydrogen sulfide measurement in demanding pipeline and gas processing environments.

Installed at fixed monitoring points, the H2S-625 provides continuous output to plant control systems, enabling automatic alarms if H2S approaches pipeline specification limits.

Specifiche principali

Range: low-ppm levels matched to pipeline quality specifications
Sensor technology: electrochemical sensor suited to continuous sour gas duty
Response time: fast enough to catch upset conditions at receipt points
Output: 4-20 mA and HART for SCADA/DCS integration
Enclosure: rugged, weatherproof housing for outdoor pipeline station use

Domande frequenti

What is the typical H₂S specification limit for pipeline gas?

Trace oxygen measurement provides a direct indication of oxygen contamination or crossover into the hydrogen stream. Trending the oxygen concentration can help operators identify changes in electrolyser or purification system performance.

How long does the H2S sensor last in continuous service?

A common measurement point is the hydrogen product stream downstream of the electrolyser stack. Additional measurement points may be used before or after drying and purification equipment depending on the process design and monitoring objectives.

Can the H2S-625 be used alongside oxygen and other gas analyzers at the same station?

Alarm and control limits should be determined based on the electrolyser manufacturer’s specifications, process conditions, applicable standards, and the facility’s safety requirements rather than using a universal oxygen alarm value.

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