Natural gas pressure regulator leak: where to check and what it means

Pressure regulators have seats, diaphragms, vents, and connections that can experience external or internal leakage.

External leakage

Check flanges, threads, body, and impulse or pilot line connections.

Leak from vent

If gas is observed in the vent line, there may be a problem with a diaphragm or other internal component. The situation must be investigated immediately.

Internal leakage

If the downstream pressure increases with zero consumption, there may be creep from the regulator seat.

Testing

Record upstream and downstream pressures, behavior at zero flow, and any presence of gas in the vent.

Safety

The regulator must not be disassembled while under pressure. Follow the established isolation and maintenance procedure.