G2419.4

Section G2419.4 is titled 'Sediment trap' and covers the requirements for providing a piping arrangement by which small solid particles within the piping system will be prevented from entering certain appliances (the section lists appliances which do not require a sediment trap). Also, the sediment trap must be installed after the appliance shut off valve, to allow for it to be cleaned out without turning off the gas to other appliances. The purpose of this section is to prevent appliance malfunction which such particles could cause. This section of the code references a figure, which is a pictorial piping arrangement required to be followed in order to be compliant. Other piping arrangements, such as the tee fitting being oriented with the straight through legs being horizontal, and the 90° (vertical) leg being used as the trap, are not compliant. In such an arrangement, the gas pressure may push the particle past the trap before gravity pulls it down.

The model shows a cutaway piping section which mirrors the figure, with the gas supply coming from the top vertical leg. (Note- The gas has been colorized for this demonstration. Natural gas is actually colorless in its natural state.) Notice the fleck of rust inside of the pipe breaking loose and ending up in the sediment trap, thus avoiding potential damage to the appliance.