There must be:
– A readily accessible manual shut off valve in the gas supply
line serving the water heater, and
– A drip leg (sediment trap) ahead of the gas control valve to
help prevent dirt and foreign materials from entering the gas
control valve.
– A flexible gas connector or a ground joint union between the
shutoff valve and control valve to permit servicing of the unit.
Be sure to check all the gas piping for leaks before lighting the
water heater. Use a soapy water solution, not a match or open
flame. Rinse off soapy solution and wipe dry.