File:Gas supply line trap.JPG

Photo showing trap (at left, consisting of tee, down-pointing short nipple, and cap) in supply line to gas water heater. Trap is intended to catch any bits of foreign material before they can enter the burner for the water heater, where they might clog the orifices or filters in the regulator or the burner.

Photo self-made by User:Ummit on 3 August 2007.

See also Image:Natural gas regulator.jpg.