Begin With the Future in Mind: Pros and Cons of Various Pipe Materials
When conducting sewer pipe installation contractors must consider many factors when deciding which type of pipe material to use.
Which Type of Pipe Material Should You Use for Your Next Project?
The most common type of sewage and water pipe materials are concrete, steel, clay and plastic (HDPE and PVC). Below, we’ve outlined some benefits and shortcomings of each type so that you are educated on the most appropriate material for your next project from a perspective of future inspections.
Types of Pipe Material: Basic Pros and Cons
High-density polyethylene (HDPE) and polyvinyl chloride (PVC) are two different materials, yet they contain many similarities when discussing sewer pipe applications. For that reason, we’ll refer to both as just “plastic” and consider them together.
Plastic is a preferred piping material given its lightweight, long lifespan (50-100 years) and ability to be procured in different lengths. Best of all, it is a practical material for earthquake-prone areas, such as the Pacific Northwest.
Plastic pipe can be prone to cracking and ingress, and as such requires frequent performance checks. Neither type of plastic pipe can withstand high heat, which can make them susceptible to bending or warping.
During inspections, it can be more difficult for traditional inspection methods such as CCTV to see defects due to darker colors of some pipes. When there is slime or debris in the pipe and it hasn’t been recently cleaned, pipe crawlers with regular wheel materials such as rubber or pneumatic tires will slip, so having a high traction material tire such as carbide is important, particularly in the flat surface PVC pipe.
Clay is more common with older installations than with new projects. It isn’t used too often today.
It does have its pros – it resists chemicals and erosion, which is why we see clay pipe persistent from days gone by. It is also more cost effective than steel or iron and has the longest lifespan in comparison to other materials. However, considering inspections, traction can be an issue, so it is important to have heavier material with grit such as carbide. CCTV is a great way to inspect clay since it is much easier to evaluate tree roots infiltration.
Steel is a popular material for potable water pipes, but can also be used for sewer pipes. Its main benefit is its strength, durability, and resistance to buildup and corrosion.
The drawback is its lifespan, which is the shortest of the types listed here. It’s also the most expensive type of pipe.
Corrugated steel is a bumpy surface, meaning that it is important to have a level tracked vehicle to traverse. Also, corrosion is typically difficult to monitor from a CCTV vehicle, as it cannot easily ascertain the extent of the corrosion as generally the corrosion occurs from the outside of the pipe.
Concrete is the popular choice for many contractors, as it performs well in both lifespan and durability. It can withstand high-pressure conditions without compromising integrity or allowing intrusion from tree roots.
Concrete does require regular maintenance in order to limit the buildup that occurs from sewage material. Regular inspections are recommended to assess the condition of the pipes. Concrete is susceptible to breaking when handled, so it must be installed with care and the proper equipment.
Concrete is ideal for CCTV inspection, since issues in concrete are much more easily determined with a camera. Traction is also not an issue even with regular build up.
Read WinCan Series 2: Coding Software for Pipe Inspections
Which Crawler Tires Are Best For Which Pipe Material?
When looking at a pipe crawler, it is important to understand that different pipe materials require different tires in order to maximize performance and travel through a pipe.
Pipe size is also a big consideration. Pipe crawlers can be designed to place the camera in the center of the pipe. Therefore, it is important in larger diameters to widen the base of the crawler to maintain stability and increase maneuverability.
Concrete is best inspected with a crawler fitted with rubber tires. Large tread rubber can grip on concrete even when there is slime or debris. When looking at Deep Trekker crawlers, diameter plays a factor in what tire selection to make.
6” – DT320, 6” Rubber Wheel Kit
8-12” – DT320, 6”/8” Rubber Wheel Kit – DT340 S – 8”/10”/12”
14” and larger – DT340 X – 12” Rubber Wheel Kit
Corrugated Steel pipe is “wavy” in shape, so when you drive a regular wheeled vehicle down a pipe it will bounce down the pipe. This isn’t harmful to the vehicle, but can make for a bumpier video. Tracks help to alleviate this since they allow for a smooth ride across the grooves, but tracks are best suited for larger diameter pipe (over 24”). Rubber wheels will have no issues with traction, so if a little bump in the video is okay, you can use these as well.
6” – DT320, Base Tracks, 6” Rubber Wheels
8-24” – DT340 8”- 12” Rubber Wheel Kits
24”+ – DT340 Tracks
HDPE has grooves similar to corrugated steel, however it is usually spaced closer together so the “bump” effect in the video is limited. PVC, when wet and slimy, as sewers get, will cause a rubber or pneumatic tired vehicle to slip particularly at longer distances. Having weighted tires with extra “grit” such as a carbide tire set is important for getting traction. HDPE is less prone to slipping due to the grooves.
8-24” – DT340 – 8-12” Rubber, 8-10” Carbide
6-12” – DT320 – 6-8” Rubber, 6-8” Carbide
24”+ – DT340 Tracks
6-12” – DT320 – 6-8” Carbides
8”-12” – DT340 – 8” Carbides
10”+ – DT340 10” Carbides
Clay is also susceptible to slipping with a crawler vehicle, so the same wheel recommendations apply as Plastic/PVC.
There are other materials used for pipes, such as Brick, Cast Iron or even Wood. Standard Rubber tires have no trouble in these materials.