Quick answer: place fixed detection where gas is most likely to be released and where people work - separators and treaters, compressor stations, tank batteries and confined spaces. H2S and combustible (%LEL) sensors are the core pair, with O2 and CO added where the process calls for them. Wireless points extend coverage to remote or temporary locations.
The gas hazards
- Methane (CH4) - the primary combustible hazard in production and pipeline operations; its lower explosive limit is 5% by volume in air (NIOSH).
- Hydrogen sulfide (H2S) - highly toxic, found in sour gas and produced water; NIOSH lists its IDLH at 100 ppm.
- VOCs, propane, carbon monoxide and oxygen depletion - from processing, LPG storage, combustion equipment and inerted vessels.
Where fixed detection fits
- Processing units and production facilities
- Separators and treaters (H2S and CO)
- Compressor stations
- Confined spaces such as tanks and pits
- Control rooms and plant perimeters
Where wireless fits
- Remote and unmanned locations
- Turnarounds and maintenance
- Emergency response
- Perimeter gas-migration tracking
Regulations to know
OSHA Process Safety Management (29 CFR 1910.119) and EPA Risk Management Program (40 CFR Part 68) apply to facilities handling covered chemicals above threshold quantities. OSHA Permit-Required Confined Spaces (29 CFR 1910.146) applies to tanks, pits and similar spaces.
Safeguard products that apply
- SA-220 Fixed Gas Detector - single sensor, 4-20 mA and Modbus output, optional relays, rated -40 °C to +60 °C. Hazardous-location certification is in progress and not yet held.
- SA-XES - aspirated multi-sensor gas detection system.
- SCX Gas Detection Control System - central control and relays.
- Foresight - monitoring, analytics and compliance reporting.
Local sensors, controllers and safety relays operate independently and do not require cloud connectivity; Foresight adds monitoring, analytics and compliance reporting on top.
FAQ
Do I need both H2S and LEL sensors? In sour service, usually yes - the toxic and explosive hazards are separate. Confirm against your site's hazard assessment.
Can readings feed my SCADA or DCS? Yes - readings are available over 4-20 mA and Modbus.
Exposure limits cited are from OSHA and NIOSH. Confirm detector selection and placement against your site's hazard assessment, and verify specifications with Safeguard before specifying equipment.