1.Why Are Trace Propylene (C₃H₆)  Leaks Always Missed?

In an ethylene plant area, an operator noticed a slight leak at the seal of a propylene compressor, but the handheld detector showed "0ppm". It only alarmed when the concentration rose to 500ppm — far exceeding the early warning value of 200ppm. The reason is that traditional catalytic combustion sensors have a delayed response to low-concentration propylene.

2.Precautions for Propylene (C₃H₆) Detection.

a.Hazardous Properties of Propylene.

Explosionlimit: 2.4%~10.3%, prone to explosion when exposed to static electricity.

Occupational exposure limit: 400ppm (8-hour time-weighted average).

b.Detection Difficulties.

When the concentration is <100ppm, the response time of catalytic combustion sensors exceeds 60 seconds.

High humidity (>90% RH) can reduce sensor sensitivity by 40%.

c.Safety Specifications.

Online monitoring points must be installed at the flanges of propylene pipelines, with a sampling frequency of ≥1 time/second.

Portable instruments should be calibrated with 50ppm propylene standard gas weekly.

3.Solution.

MST 410P Portable Pumping Multi-gas Detector

✔ Equipped with an infrared sensor, with a response time of <3 seconds within the 0-1000ppm range, ensuring no lag in low-concentration detection

✔ IP66 waterproof and dustproof, suitable for high-humidity environments in petrochemical workshops

✔ Built-in pump-suction sampling with a built-in extended detection tube, enabling detection of hidden leak points such as pipeline gaps

✔ Accessories include a float, allowing underwater gas detection

After replacing the sensor in a petrochemical plant, the detection time for propylene leaks was shortened from 5 minutes to 10 seconds.