Trenchless Rehabilitation for Gas Lines: How to Detect a Gas Leak
Pay attention to the subtle signs around your home. If you see any gas-leak indicators, it's time to call someone to inspect and repair the pipelines.
A faulty gas line is nothing to mess with when you are a homeowner. A gas leak is dangerous, not just to the health of the occupants, but also to the safety of those living in the immediate area.
What are some ways to tell if your home may be suffering from a gas leak and how do you fix it?
How to Detect a Gas Leak
Of all the signs, the best one is the smell. Naturally-occurring carbon monoxide is odorless. However, due to its dangerous nature, gas companies put an additive into their system which gives it a sulfur smell similar to the smell of rotten eggs. This additive allows you to smell when there is a leak. (Do you know What to Do When You Smell Gas?)
Another indicator lies within gas-based appliances such as stoves and furnaces. When these are not putting off the same amount of heat or flame as they once did, it can be an indicator of a gas leak. While this could be an appliance issue, most likely it is because they are not getting the amount of fuel they once did, indicating a break somewhere in the gas line.
If your gas appliances start making noises when being used, this is an indication that there is a break in the gas line somewhere. The noise could be a clanging or groaning sound that it never made before. In either of these situations, turn off all appliances and check your meter. If the meter is still moving, there may be a leak.
Most people would not connect their landscaping to a gas leak, but a break in the gas line could cause your grass or shrubbery to turn brown, as the carbon monoxide is blocking the oxygen from reaching the live foliage. Water them at the brown areas.
If you see bubbling at the ground, there's a leak.
Trenchless Inspections for Gas Leaks
In any of these instances mentioned above, you should not try to locate the leak yourself. Instead, call a plumber to come out an inspect the lines to determine the break for you. A specialist will use one of a couple of different ways to examine the pipeline and find the leak. (Read Prevention Is Better Than Cure: How Remote Pipeline Inspections Save You Time and Money.)
One way to inspect the gas line is with video inspection equipment. This method is called a closed-circuit television inspection (CCTVI), which uses CCTV technology. In this case, the plumber will use a camera inserted into the pipe. The camera transverses the area and sends a signal back to the operator.
The operator may use one of three main types of cameras:
The Push Camera Method
A push camera is attached to a long line. The line is inserted and pushed through the pipe. Someone must operate the line, moving it forward manually while another operator views the video feed.
Push cameras cannot branch off into separate lines, so the operator must inspect each gas line looking for a break.
Here's an example of a push camera in action:
The Lateral Launch Camera Method
A lateral launch is like a push camera. However, this video inspection tool is not manipulated manually as the push cam is. The benefit of this camera is that it comes equipped with a second camera, which can be deployed along branch lines.
Inspectors may also use a robotic camera to perform the inspection. These are autonomous robots with cameras attached and driven by remote through the gas line. The most significant benefit with robotic cameras is the ability to turn the lens 360-degrees and view the entire pipe.
Some inspectors, however, may choose to use a technique known as pigging. (Learn more in How Pigging Works in Trenchless Repair and Rehabilitation.)
A pipeline inspection gauge, or PIG, goes into the line and relays data back to the operator. The PIG cleans and measures wall thickness and for cracks or damage to the pipe using ultrasonic and magnetic flux testing. (Learn more in this comparison: Understanding the Differences Between Pigging and Robotic Pipe Inspection Methods.)
While there is no video feed on this tool, it is a useful method of finding corrosion and metal loss in gas lines.
Trenchless Repairs for Gas Leaks
Once the plumber locates the leak, he can make repairs. Traditional trenching repairs can take several weeks to complete, especially if the broken line is underneath the house. Trenchless rehabilitation, however, is often the preferred choice as it is quicker and safer for those involved.
As the name indicates, pipelining is when a new line goes into the existing pipeline.
Sliplining is the most common technique for straight segments of damaged plumbing. Plumbers insert a hard PVC or polyurethane tube into the damaged line. It is a smaller diameter than the existing portion. However, the current tubing acts as a sheath adding structural support and protection.
Sliplining only works on straight sections and cannot line pipes around bends. (Here's An Overview of Sliplining.)
For pipes with bends that need lining, the plumber may suggest using cured-in-place-pipe (CIPP). Unlike sliplining, CIPP uses a flexible fiberglass tube impregnated with resin. (Read Is a CIPP Liner The Right Fit for Your Trenchless Rehabilitation Project?)
Workers pull the tubing through the pipeline. If there are bends in the existing structure, the CIPP line flows around it, making a new hard pipe with no connection joints. Once the fiberglass is in place, it hardens into the new pipeline.
Watch this CIPP demo:
The lining does not work on all pipes. Sometimes the property needs a new line. Pipe bursting allows the plumber to lay new plumbing without digging up the old. In this case, the workers dig two small trenches, one at the entry and the other at the exit point. (Quiz yourself with: The Trenchless Pipe Bursting Rehabilitation Method.)
They run a cable through the existing pipe. At the end of the cable is a bursting head. As the cable is pulled through, the bursting head breaks up the tube.
The new line follows the bursting head sliding into the place vacated by the old plumbing. (Read on in An Introduction to Pipe Bursting.)
Pipe bursting allows brand new pipe made of stronger material to be installed without trenching. The new pipeline can also be a bigger diameter if needed.
Pay attention to the subtle signs around your home. If you see any indicators, it is time to call someone to inspect and repair the pipelines.