Catching particulates in gas pipes

I've always put a "dirt leg" close to the connection for each gas applicance (dryer, water heater, furnace, range, etc. Usually right before the valve for the appliance.

HTH,

Paul F.

MC-

As Paul posted, that has been my experience and how I have done installs but.........in my house the furnace has one, the water water & stove do not. Owned this house for 30 years & have had no problems with any of the gas appliances.

I wonder if the "dirt leg", as Paul calls it, is ancient practice that has no real value kinda like "air chambers" made of a foot or so of pipe.

I was told years ago that the "dirt leg" was really a "condensate trap" ...........

cheers Bob

One trap per appliance.

On natural gas powered generators I've always installed not only a drop leg but also a Y strainer to keep debris out of the system.

Needing to replace appliances I have checked the dirt traps and never found anything in them.........

gas company must be careful dirt might muck up meters, and their regulators.

although a broken underground water line can get water into gas lines its occured around here.

on 2/3/2009 12:21 AM (ET) Paul Franklin wrote the following:

I was told it was a condensate trap. If you put it before the valve, how would you inspect or empty whatever it collected? Mine are after the valve so I just have to shut off the valve to that appliance to check the trap and not the whole house valve, or in my case, the valve on the top of my propane tank.

ALL gas appliances require a drip leg at each appliance unless you like to replace gas valves, regulators, etc. These are there to catch oils, pipe dope, metal shavings, water and anything else that can get into the gas piping supply. Also, never use copper for natural gas lines. It causes the inside of the copper to oxidize and flake off causing all kinds of particles to go through the gas line. Bubba

I've heard it called a "drip leg". May very possibly do both?

How often do you inspect them? Ever find anything in them?

I've never opened one, even on our big gas boilers that are 5,500,000 Btu.

I don't think they were ever intended to catch much water or debris but are just a cheap, simple, extra bit of "just-in-case" insurance. It probably would be worth it if it caught one tiny piece that could clog an orfice or prevent a valve from seating.

It is probably not revelant but I once had an underground gas feeder that collected enough water to cut off my supply. The gas company disconnected the line and blew the water out. So I know it is possible for water to make its way into gas lines.

Don Young

plumber I know reports they are no longer required

do u know what a dirt trap is, henry, if not i will explain