UTL/General/TBT-UTL-018

Gas Pressure Reduction and Control

Utilities & Network Infrastructure › General › Gas Pressure Reduction and Control

Presenter		Project
Location		Date

Gas pressure reduction stations reduce high-pressure gas to lower distribution pressures for safe delivery to consumers.
Operating pressures in gas networks range from 7 bar (medium pressure) to 70+ bar (high pressure transmission).
Work on gas pressure reduction equipment must be carried out by gas-competent engineers registered with the network operator.
Gas leaks during maintenance or installation create explosion and asphyxiation hazards in the immediate area.
Pressure regulators, slam-shut valves, and relief valves are safety-critical components requiring specialist knowledge.
The Gas Safety (Installation and Use) Regulations 1998 and IGEM standards govern gas pressure reduction work.
Venting gas during maintenance creates a flammable atmosphere — exclusion zones and ignition source control are essential.
Cold burns can occur when high-pressure gas expands rapidly through regulators and relief valves.
ATEX zones around gas pressure reduction equipment prohibit ignition sources including mobile phones and cameras.
Emergency shutdown procedures must be understood by all personnel before work on live gas systems begins.

Explosion risk	Gas leaks in pressure reduction stations create explosive atmospheres — ignition causes catastrophic explosions.
Asphyxiation	Vented gas displaces oxygen in enclosed areas, causing unconsciousness and death within minutes.
Legal compliance	The Gas Safety Regulations 1998 and IGEM standards require competent persons and strict procedures for all gas work.

Don't

Confirm all personnel are gas-competent and registered with the network operator before starting
Establish ATEX exclusion zones and remove all ignition sources from the work area
Use continuous gas detection monitoring throughout all work on pressure reduction equipment
Follow the approved method statement and permit to work for every task on gas systems
Ensure the emergency shutdown procedure is briefed and understood by all personnel on site
Vent gas safely to atmosphere using approved vent stacks away from buildings and ignition sources
Wear appropriate PPE including anti-static clothing in the ATEX-classified work zone
Test all connections and joints for leaks using approved leak detection fluid before re-pressurising
Maintain communication with the gas network control room throughout the work period
Purge pipework and equipment with nitrogen or an approved inert gas before breaking joints

DON'T work on gas pressure reduction equipment without valid gas competency registration
DON'T use mobile phones, cameras, or unapproved electrical equipment in ATEX zones
DON'T vent gas near buildings, air intakes, or ignition sources without safe vent arrangements
DON'T break joints on pressurised gas pipework without confirmed isolation and depressurisation
DON'T enter areas where gas is venting without continuous gas detection and RPE if required
DON'T use non-spark-free tools on gas equipment in ATEX-classified hazardous areas
DON'T re-pressurise systems without completing and passing a leak test on all connections
DON'T touch cold metal surfaces near expanding gas without thermal-protective gloves
DON'T carry out welding or hot works near gas equipment without a specific permit and controls
DON'T override slam-shut valves or safety relief systems without network operator authorisation

See also: Gas Main Installation Safety | Gas Escape and Emergency Procedures

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