Environmental health practices require private homes and businesses, along with state-owned institutions to discharge their waste fluids into the local sewerage (infrastructure) system, which is usually maintained by the local authorities.
This sewer system conveys sewage fluids and surface runoff water, including rainwater, storm-water, and meltwater, from the human-inhabited space into a sewage treatment plant, or any other exit point where it discharges the (treated or untreated) sewage into the environment.
This sewerage infrastructure is made up of drains (of the drainage system), chambers (most of which are accessed through manholes [also called access holes]), and the ever-critical pipe system that conveys the waste fluids to the treatment plant or discharge point.
The aforementioned infrastructure is the core of the sanitary (or foul) sewer whose system of underground carriage (piping) transports sewage.
It can also be used to transport industrial waste fluids. In this pipe system, the pipes are placed underground in a declined position so that waste fluids enter a pipe from the relatively raised pipe inlet, then flows down a gradient to the pipe outlet.
Because waste fluids can flow down the piping by the force of gravity, this form of sewerage infrastructure system is known as a gravity sewer.
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Plumbing from building to sewer
Even so, waste fluids need to be conveyed from their points of production – which are located inside homes, commercial buildings, and industrial production lines – to the sanitary sewer line.
This requires homes to have a fully-functional sewer plumbing that can convey waste fluids from the bath-tub, washbowl, toilet, and basin suites into the sanitary sewer line.
There also needs to be a separate plumbing for conveying rain water down the roof into the gutter, then into the downspout, and finally into the storm sewer pipe.
Likewise, the roadside drainage system must have a series of catch basins (preferably with traps installed) that allows surface run-off water to drain into the storm sewer line.
Along the sanitary sewer and storm sewer lines are a number of vertical pipes that can be accessed from the surface, and they are called test tees.
They allow for easy access to the underground pipe system during inspection and maintenance duties.
Non-Destructive Sewer Video Inspection
As is evident, the pipe network is the backbone of any sewer system; and if the pipes get blocked, then the sewer system malfunctions, and in extreme cases is rendered non-functional.
Even so, the pipes that form these piping network are hidden from view, either inside the wall in homes, or underground in the case of sanitary and storm sewer pipes.
So, how does one inspect the pipes during regular maintenance, or when trying to identify a fault that is causing sewer leakage, or to locate a block in the pipes?
The answer is that one needs to perform a procedure called sewer video inspection, and this is done using a special set of equipment called a sewer inspection camera unit.
The sewer inspection camera unit
This form of inspection pre-empts the use of destructive, time-consuming procedures such as digging for pipes, and expensive dismounting work such as manhole removal and pipe retrieval from the ground.
Therefore, sewer video inspection is a non-destructive testing technique that allows for recognition and location of defects and structural imperfections along the sewer line.
This procedure involves running a video line through the pipes so as to capture real-time images, as well as record videos that can assist in maintenance and repair work.
The equipment that captures the images and records the images is the inspection camera – which makes it the most important component of this unit.
The Sewer Inspection Camera
The acrid waste fluids in the sewer lines contain the highly corrosive chemical, hydrogen sulfide, that is associated with biogenic sulfide corrosion which necessitates pipe rehabilitation.
This indicates that video inspection must be done using corrosive-resistant equipment, and since it is the inspection camera that goes into the pipe, it must not only be able to withstand acid corrosion but must also be fully waterproof.
Design-wise, the visual inspection equipment is normally designed as a borescope.
This means that the inspection camera is fitted to one end of a tube, while the other end of this tube terminates into a monitor hub whose screen displays what is being seen by the camera.
For high-end inspection kits, a standard, or highly-customized relay optical system is fitted between the monitor hub and the camera so as to improve the quality of videos and images seen by the user.
If the tube used is flexible and made from a single or a bundled set of optical fibers, then it is known as a fiberscope.
The flexibility of the fiberscope allows it to bend inside the pipe so as to move through pipe bends and the angled junctions of two pipes.
Moreover, use of multiple optical fibers improves the image quality as it can reliably relay a pixel-dense image captured by the camera.
In some high-end models, these optical fibers are arranged to create a functional visual grid that improves pixilation and minimizes pixel cross-talk.
Sewer Camera clarity
The clarity of videos and images captured can be improved by enhancing the lighting at the area being viewed.
This is done by adjusting and controlling the LED (light-emitting diodes) that are fitted on (and in high -quality models, surround) the miniature video camera.
In some models, the LED lights are fitted at the end of the fiberscope (which can now be best described as the insertion probe). This allows for better remote visual inspection of dark spaces inside sewer pipes.
Also, the LED lights and miniaturized video camera at the end of the insertion probe must be supplied with electric power, and this means that the insertion probe must convey electric cables from the power source to these 2 electrical appliances.
The power source can be a battery or a socket outlet. The battery-operated inspection camera is usually better as it is portable, and can be used in off-grid locations, or places inside a house or building where there is no socket nearby.
This makes them fully portable as compared to models that have conventional power cords whose portability is limited by the length of their power cords, that is, they can only be moved far away from the socket as determined by their cable limit.
Snake Camera Flexibility
The use of a flexible and submersible insertion probe that can move easily through pipe bends and then change direction at pipe junctions has justified the use of the descriptive term, snake camera.
Also, the fact that the fiberscope (insertion probe) is illuminated at one end has led to some users and traders calling it an endoscope.
Even so, this term is misleading as an endoscope is usually a flexible illuminated fiberscope that is used to view the gastrointestinal tract of humans and animals, that is, it is a biological utility appliance.
The use of video inspection in plumbing maintenance and troubleshooting shows how modern technology has revolutionized blue-collar work; and for one to get the maximum benefit from it, then one needs to acquire a high-quality inspection camera.