AskCodeMan

Jerry,

As you know many of our fellow HIs in this market have been lobbying the local AHJ's to actually follow the IRC when it comes to installing "sediment traps" on the gas supply lines for furnaces and water heaters. Seldom do we see them and when we do they are often not installed correctly.

I think that many times when we do see them ... we're taken aback by surprise and then don't look closely to see if they have been properly installed.

All that being said ... I've attached some images from a NHF (New Home Final) inspection I did yesterday in Frisco, TX (Northern suburb of Dallas) where the builder had actually had the sediment traps installed. One is 'almost' correct, but two were not. Now that is my view/interpretation and is likely open for comment.

It is just nice to see that we are making progress.

Hi Nolan,

Yes, I know that HIs in your area have been asking local AHJ about sediment traps and why sediment traps have not been enforced in the past, and that in doing so many of your local AHJ are now enforcing the installation of sediments traps, as required by the IRC.

Yes, it does take time for things to change, eventually all (hopefully all) local AHJ all over the country will enforce the requirement for the installation of sediment traps in gas lines. Then the contractors, who already should know that sediment traps are required by code, and who should already know how to configure sediment traps, will know to install the sediment traps without being forced to do so by the local AHJ, and the contractors will know how to configure sediment traps.

The IRC specifically requires sediment traps (with a few excepted locations) and the IRC Commentary explains and shows how to configure sediment traps. The IRC Commentary also shows a photograph of a prohibited sediment trap configuration.

The following is the 2006 IRC section regarding sediment traps. (underlining and bold are mine)
- G2419.4 (408.4) Sediment trap. Where a sediment trap is not incorporated as part of the gas utilization equipment, a sediment trap shall be installed downstream of the equipment shutoff valve as close to the inlet of the equipment as practical. The sediment trap shall be either a tee fitting with a capped nipple in the bottom opening of the run of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers and outdoor grills need not be so equipped.

The sediment trap shown in your photo Sediment Trap #3 is basically correct, however it raises concerns on the supporting and securing of the pipe.

The sediment traps shown in your photos Sediment Trap #1 and #2 show an incorrect configuration as the gas should enter the sediment trap vertically down from the top, with the trap nipple vertically below to catch and collect any debris, with the gas outlet the side outlet of the tee, not as shown with the gas entering the tee from the side outlet of the tee. With these configurations, the debris can keep flowing along with the gas flow to the gas valve and the burner, clogging same.

Explicit reading of the IRC Commentary, though, is not specific as to which way the gas is to be connected, however, with the gas connected as shown in your photos #1 and #2, the gas does nothing more than make a 90 degree turn, the same 90 degree turn the gas has made through each elbow in the gas line and which has allowed the debris to get to the sediment trap, thus, with the gas entering vertically from the top, the debris does not make the 90 degree turn with the gas as the debris is carried on down into the sediment trap leg at the bottom of the nipple.

The two attached images are from the IRC Commentary, one shows the correct configuration for sediment traps and the other shows a typical prohibited configuration - which is not even is close to the proper configuration as the ones in your photos.

Codeman