Utility Inspection Systems and Their Benefits
It is obvious that knowing the condition of underground sewer and water infrastructure is necessary to properly maintain essential services, and today’s CCTV (closed circuit television) inspection systems visually identify structural and maintenance issues like cracks, broken or collapsed pipe, infiltration, grease, and roots, as well as other issues.
Mainline inspection equipment is routinely used by municipalities, water and sewer districts and contractors for inspecting 6-inch and larger sanitary storm drain sewer pipelines. Smaller pipelines, 4 inches and less, are typically inspected with a push camera system and are accessed from the sewer cleanout or other entry points inside the house.
During an inspection, data collection software will used to identify the assets being inspected as well as log observations of defects and maintenance issues. Pipeline Acescent Certification Program (PACP) has a standard coding system, developed by the National Association of Sewer Service Companies (NASSCO). This tool is used for gathering common data that can be sorted by type of defect and severity of defect and allow an engineer to easily identify what pipes need to be addressed immediately, and how to address the defect.
Basic components of a CCTV pipe inspection system are:
- Camera or camera/transporter unit
- Power supply/control unit
- Reel and cable system
The type of inspection system used is based on the size of the pipe and the conditions that are present in the pipeline. Inspection system can range from a simple push camera system that is manually push through a pipeline using a fiberglass reinforced cable to a portable system that can be wheeled into a tight access area like a backyard or an easement to a vehicle mounted system that is designed for inspecting thousands of feet of pipeline per day and houses all of the equipment and it’s supporting items. Control components are mounted in a van or truck.
Push Camera Systems
Push camera systems are used for inspections of smaller pipelines (1-1/2-inch up to 12 inches) like sewer laterals, household plumbing, or floor drains. The reel assembly will have options for push cable lengths between 100 feet and 500 feet. The push camera can enter the pipeline through a cleanout located usually on the outside of the house or it can enter through an access in the house by removing a toilet. It can also enter through a vent line on the roof of the house. The system can be hand carried into a house or wheeled into a yard and will operate on 120 volts AC or on a 12-volt battery that is built into the system. The fiberglass reinforced cable is on a reel/spool and the operator enters the camera into the pipeline and manually feeds cable from the reel and into the pipeline pushing the camera down the pipeline.
The power/control system, mounted in a portable case, has a TV monitor and a recording device so the operator can view the pipeline condition as they push the camera and record the video at the same time. The cable reel has a counter built-in and the footage is overlaid on the video and is seen on the TV monitor. The operator will stop at observations that they want to verbally note on the recording using the built-in microphone on controller. There are more expensive systems that will allow the operator to log the observations in a data collection software real time or they can do this as a post process to the actual inspection.
Portable and Transportable Systems
When larger pipelines (6 inches or larger) are to be inspected and have the proper access for a robotic system to be used, a portable system is recommended. This system will grant the operator more capabilities and options. The robotics systems will have a camera that can pan side-to-side and rotate clockwise and counterclockwise to allow the operator to look directly at an observation and see better details. This pan and tilt camera is mounted on a transporter that is powered by a cable that it tows behind it. The cable allows the operator to control the camera and the transporter as it powers both units and transmits the video back to the control station. The cable is loaded on a motorized reel that also has a built-in footage counter to track and display the distance the transporter has traveled. The cable reel holds up to 1,000 feet of cable and includes a level wind system to manage the cable paying on and off the reel. The control system is housed in a portable case and can be mounted on the reel or removed for easy transportation of the entire system.
There are also transportable systems that consist of an enclosure, like a cube, that the entire system is mounted in and is designed with storage for the accessories. The cube can be lifted with a forklift or a backhoe. This unit can fit in the back of a truck or on an ATV. The unit is designed to mount an EU 2200 generator that can operate while still inside of the enclosure and has an onboard water tank, 12-volt DC water pump, and hose reel to clean off the equipment after performing an inspection.
Vehicle Mounted Systems
Vehicle mounted systems (VMS) are most common for production type work like municipalities self-performing their inspection programs or for contractors inspecting new construction installations. The VMSs have multiple options for onboard power sources based on vehicle type and vehicle fuel type. Typical vehicle types are high cube trucks, commercial vans (like Sprinter or Transit) and 8 feet to 16 feet long trailers. The installation consists of two spaces: the office space that is climate controlled and ergonomically designed for the operation of the inspection system and the equipment room that contains the cable reel and other support equipment as well as tool storage, washdown system, sink, and cabinetry for additional item storage. The two are separated by a wall with a window for a complete visual of the equipment and the access area for the pipeline.
The portable, transportable and VMS systems all have the capability to run any mainline inspection equipment. This would include all wheeled transporters as well as crawlers (track unit). Other methods of inspection include floating, sonar profiling, and laser profiling.
Most cameras are compatible with multiple transporters and have options for inclination (the measurement of foot of fall or percent of fall over distance) and laser diodes to assist in measuring defects in the pipeline.
While the portable and transportable systems are limited to 1,500 feet of cable the VMS systems have options up to 2,500 feet of our double steal armored Single Conductor Cable that has 5,400 pounds of breaking strength and is only a quarter inch in diameter. The single-conductor technology is a version of the same coaxial cable that reliably delivers hundreds of TV channels, high-speed internet, voice communication, and more to millions of households and businesses across America. The advantages over competitive multi-conductor cable are clear:
- Video signal quality is not affected by the length of cable (unlike multi-conductor technology).
- Single-conductor cables offer a life expectancy at least three times that of any multi-conductor cable.
- Single-conductor cable has a breaking strength greater than 5,000 pounds (typical multi-conductor cable has a breaking strength of 2,000 pounds or less).
- Single-conductor cable is simple to maintain, and the end connectors can be replaced in a matter of minutes. Multi-conductor cable typically requires several hours of labor and advanced technical skills to splice or troubleshoot multiple wires.
The cable has a coax inside and has only two wires (hot wire and a ground) to carry all the power and control signals as well as transmits the video back to the control unit. This simplifies the system and makes trouble shooting a breeze. With the double steal amour protection cable damage and failure is almost nonexistent.
Mainline inspection systems have optional software choices and many of the software companies have different levels of software they provide based on the needs of the owner.
The basic or lite software option allows the operator to enter very basic information about the pipeline and assets. Common entries would be start and end point IDs, pipeline ID, location, size, material and use (sewer, storm, etc.). The system will also typically include a video encoder so you can digitally store the video on the computer as well as an overlay system that overlays certain data fields from the information that was entered, footage reading, start/end IDs, on the screen and in the video.
Once the setup is complete and the operator starts driving down the pipe, they will use a list of pre-determined codes to identify maintenance issue or defects in the pipeline. When the observation is completed a picture with location or footage is logged in the database along with any notes the operator enters. When the inspection is complete a report can be generated that will list the data information entered and all the observations that were logged with a graphic format. This graphical format is like a stick figure of the inspection and when a lateral is logged at the three o’clock position in the pipe it shows up on the right side of the line representing the pipeline. The report will also include the pictures that were taken at each observation so whoever is viewing the report can see right away what the operator was seeing.
All this information can be exported from the computer to a DVD, jump drive, or other media.
Pipeline inspection equipment works in harsh environments and will require proper maintenance to maximize performance and minimize downtime. One main maintenance item is properly cleaning the equipment daily to remove debris, grease and harsh chemicals that can accelerate corrosion. There are several store-bought disinfectant cleaners that can be used for this. The other important maintenance item is testing the cameras and transporters for leaks. This should be done daily. If damage is caused to the equipment it should be checked right away before reentering the pipeline.
Training and Safety
To achieve maximum performance from the inspection equipment quality training is a must. Factory trainers or certified trainers are the best solution to receive proper training of operation and maintenance of the equipment. Depending on the user’s experience, a mainline system training would take one to two days and if additional equipment was purchased like a float system or a lateral launch system an additional one to two days may be needed. Sometimes breaking up the training into multiple visits can be beneficial to allow the operator to get familiar with one aspect of the system first, like the standard mainline camera and transporter, and then come back and train the other product like the lateral launch system. If you have employee turnover it is always a good idea to have a trainer do a refresher or a new training session to make sure no bad habits are passed along.
Contributed by SubsiteRead the Full Article