Is an undersized gas line a safety concern?
As a designer I often run into undersized gas lines. This normally happens when more gas load is added to a correctly sized gas line. For example, you have a 1” line serving a total load of 148 cubic feet per hour at a maximum length of 100 ft., but then you decided to add one more appliance that uses 50 cubic feet per hour of natural gas. The existing one-inch gas line now becomes undersized. When all appliances are simultaneously working, the equipment that is farthest from the gas meter will hurt and you will not have the necessary gas flow to make the equipment run at its optimum condition.
When does an undersized gas line become a safety issue?
In most cases an undersized gas line is not a safety concern. If an appliance were going to use 100 Cubic feet per hour of gas, and now, because of the undersized gas line, it is getting only 50 cubic feet per hour then the appliance is only going to produce half the amount of heat it would have produced with the correctly sized gas line. But under-performance of an appliance is not a direct safety concern. It is just a myth that an undersized gas line helps build Carbon monoxide. A combustion process using a hydrocarbon (such as the natural gas or Propane) produces Carbon dioxide and water (Carbon of the hydro-carbon fuel binding with Oxygen to produce CO2, and Hydrogen of the hydro-carbon fuel binding with Oxygen to produce water). Carbon monoxide is produced when there is incomplete combustion i.e., there is a shortage of Oxygen (air). An undersized gas line WILL NOT produce CO because you are not cutting down on air (Oxygen), you are reducing the amount of hydrocarbon to be burned.
An undersized gas line can be a safety concern in a quite different scenario. Imagine a burner working with the optimum amount of fuel (gas) and air being delivered to it. Now start reducing the amount of gas to the burner but keep the air coming in. If the excess amount of air can put out the fire, then you have stopped the combustion process, but you still have the gas flowing to the burner. In such a scenario the gas buildup can be a serious safety concern.
Tags: Low gas flow, health hazard, safety hazard, explosion, gas pipe sizing, gas line sizing, gas sizing, natural gas, Propane, Methane, Uniform Plumbing Code, Gas chart
Undersized gas line an explosion hazard?
Undersized gas line creating a health concern?
