Gas Piping and Gas Pressure

Gas piping delivers fuel from the meter or tank to each appliance at the pressure and volume the appliance requires. Two pressures matter in the field: the inlet or supply pressure to the appliance, and the manifold pressure at the burners.

Pipe sizing is about volume, not just pressure. A line can show correct static pressure with the appliance off and then drop badly once the burner fires, because the pipe cannot deliver the flow. That is why pressure is always checked with the appliance running and, ideally, with other gas appliances running too.

1. 1Connect a manometer at the inlet pressure tap of the appliance.
2. 2Record static pressure with the appliance off.
3. 3Fire the appliance and record pressure again.
4. 4Fire other gas appliances in the building and record once more.
5. 5Compare all three to the values the manufacturer specifies.
6. 6Check manifold pressure at its tap and compare to the data plate before adjusting anything.

Gas piping materials, sizing tables, joint methods, testing pressures, licensing and permits vary by jurisdiction, adopted code edition, fuel type and the manufacturer instructions.

• Digital or column manometer
• Approved leak detection solution
• Combustible gas detector
• Manufacturer data plate and instructions