A sediment trap is a short piece of gas pipe installed near an appliance that helps to collect debris in the gas line. The idea is that any debris in the gas line will collect in the sediment trap before that debris can foul up the appliance’s gas valve and cause trouble.
You’ll often hear the term “drip leg” instead of sediment trap. In fact that’s what I usually call it, but it’s not really the same thing.
A sediment trap is just a T fitting in the gas pipe with a capped pipe nipple at the bottom of the T. It’s required at a furnace, boiler, and water heater, but not at a clothes dryer, a kitchen range, or a fireplace.
The sediment trap needs to be installed downstream of the appliance’s shutoff valve and as close to the appliance as practical.
And it needs to be installed so that the gas flow changes direction, so that the debris will fall into the trap. If you install it so that the gas flows horizontally (like in the picture below) then the debris might just jump over the trap and get into the gas valve.
There’s no excuse for the lack of a sediment trap. A competent plumber knows it’s required by all relevant codes and by the appliance manufacturer’s instructions. And you don’t want an incompetent plumber installing your gas pipes. So if it’s missing that’s one strike against the plumbing system as we work on telling the story of the house.
But how bad is this problem, really? Well, I’ve heard that this might have been an issue many years ago, but today the natural gas delivered to your house generally is clean and dry. And I’ve never personally heard of a problem that occurred because of a missing sediment trap, although I have heard stories of clogged gas valves.
So have a sediment trap installed the next time the appliance is replaced. In the meantime it’ll just be one of the many things in your house that’s not perfect.
More Posts You May Find Interesting
Because the pipe that brings water into our house is buried underground we use it to as part of the grounding electrode system. This is the system that connects the neutral wires in our house
AC wire size
One of the most commonly misunderstood issues in your electrical system is what size wire and circuit breaker you need for your central air conditioner or heat pump. In this post I’ll explain the issue.
Flue Condensate Damage
When you burn natural gas perfectly you get carbon dioxide, water vapor, and heat. Here’s the chemical equation: Of course few chemical reactions are perfect, and because we’re using air instead of pure oxygen and
A double tap is when two or more wires are attached to a single circuit breaker. In most cases this isn’t allowed, because the circuit breaker is designed to accept only one wire. So if
How long does a home inspection take?
How long does a home inspection take? Of course a home inspection should take however long is necessary, but there are some general guidelines for how long to expect it to take. For a typical
Problems with clothes dryer exhaust vents are very common defects found during a home inspection. I see dryer vent problems of some type on about 75% of the inspections I do. And this isn’t just