Pipelines can become blocked or deteriorate. Routine pipeline inspections can alert homeowners and city officials to issues within their sewage lines before they become an issue. It is important to hire a trained professional to perform inspections properly.
However, sometimes even professional investigations can go wrong, and using advanced equipment can keep problems from arising.
How to Properly Perform Pipe Inspections
As visual inspections of pipes is not a feasible option, using video to search and find leaks or blockages in the pipeline is often the go-to method. The size of the pipe will dictate which type of camera workers employ. Most work occurs in pipes with a diameter of 2-36 inches. Smaller or larger lines may require a different approach.
Workers use an inlet, vault, or manhole drain as the access point to the suspected problem line. As they use a preexisting access point, there is no need to dig up the pipe before the inspection. The camera operator places the waterproof camera into the pipe.
Technicians stay topside and view the video feed on closed-circuit television. Some cameras use transmitters and receivers to transmit the video back to the operator. Other cameras use a fiber optic cable to communicate the images to the television. (Read Why Trenchless Technology is a Perfect Fit for Fiber Optic Cable Installation.)
Those with transmitters can send the GPS location within the pipe, so workers know exactly where the blockage or break is on the ground above and mark it.
What Can Go Wrong in a Pipe Inspection
While cameras are rugged, they don't always make it through inspections intact. Most commonly, the problems are damage to the camera or cabling.
One primary way that a pipe inspection can go wrong during an investigation is a kink in the pushrod. For cameras that use a push rod or fiber optic cable, going through the pipe can cause damage to the cord. Usually, this happens within the first few feet of the inspection and is caused by pushing too hard too fast.
Damage caused to the pushrod or cable can be expensive. For a re-termination repair, the cost runs from $200 to $600 (USD). The solution is to go slow when inserting the camera. When going around a bend, use short, fast motions and pay attention to where the camera is going.
The other main thing that goes wrong with a pipe inspection is damage to the camera itself. With the camera head exposed, it is easy for the lens to be damaged during the investigation. Often, the lens cover or light ring becomes cracked when it accidentally hits the pipe wall or blockage.
Careless maneuvering turns an expensive camera into a battering ram. The lens itself is protected by the cover, but it is still costly to repair.
What Equipment Is Available for Pipe Inspections
Pushcams, which are mentioned above, are the most common method of conducting pipe inspections. It’s a simple method that involves a camera attached to a long cord. The operator pushes the camera through the pipe. Operators on the surface view a live image.
The camera does not move by itself; the only way to advance the tube is for an operator to push it through the pipe. As there is no real maneuverability to the camera, it's challenging to move them down different branches of the pipeline.
Lateral Launch Cameras
A lateral launch camera is very similar to a pushcam. As with a pushcam, the operator must push the camera through the inspected mainline. However, when the operator reaches a branch in the pipeline, there is a second deployable camera to go through the branch.
This allows the operator to receive live views of both the mainline and the branch lines for an overall picture.
Submersible Pipe Crawlers
Small robotic cameras give the inspectors greater control over how they view the pipes. Instead of having to control them with a wire, workers control the camera from above-ground using a remote control. (Read Using CCTV to Inspect Pipes.)
The Deep Trekker DT340S Pipe Crawler package is an example of a small robot camera. This package includes a pan, tilt, and zoom capable camera, 150-meter tether on a reel with length counter, a handheld control and carrying cases.
The DT340S pipe crawler contains an onboard battery with an eight-hour life. The operator deploys the camera into the system, controlling it from above. Operators can rotate the camera up to 280 degrees to visualize the entire pipe on the included color closed-circuit TV.
It is ideal for the storm, sanitary, or underwater pipelines as the DT340 is submergible in up to 164 ft (50m) of water.
Pipe inspections are a necessary part of sewer maintenance. Regular inspections should occur yearly. Through remote cameras, you have a more excellent viewer range as it advances down the pipeline.