High-density polyethylene (HDPE), which is sometimes referred to as polyethylene high-density (PEHD), is an extremely durable type of plastic that has a multitude of uses from food packaging to plumbing pipes. Development of the material started in 1900, but it wasn’t used in a commercial application until 1953 when the British used the plastic to insulate their radar cables. However, HDPE wasn’t formed into a pipe until 1955. Over the last several decades, the pipes have been used for sewer lines, agricultural and industrial plumbing and in potable water applications for cold water lines. HDPE is not used for hot water lines. In buildings where HDPE is used for the plumbing system, PEX is chosen for the hot water lines.
Advantages
HDPE offers significant advantages over other types of piping materials. It is corrosion resistant and naturally inhibits the growth of certain organisms. It also offers smooth water flow, and it is resistant to the build-up of scale and lime deposits.
HDPE is extremely flexible, which allows it to be placed in a wide variety of 
spaces and environmental conditions. It is even resistant to the natural shifting of soil, which makes it perfect for underground applications, even in earthquake-prone areas.
High-density polyethylene is a unique type of plastic that can be welded. This means that joints and seams do not need fittings. Instead, they are fused together with heat, which makes them resistant to the development of leaks. If HDPE is to be connected to other piping materials, this can be accomplished by using stab-fittings or mechanical fittings.
HDPE can be installed trenchlessly, which is less disruptive to the environment. It also requires less labor and less time to install the pipes. During a trenchless HDPE pipe installation, an underground hole is bored. Once the end of the hole is reached, the pipe is attached to the drilling mechanism and pulled through backward as the drill is removed.
When the HDPE is no longer needed or they have reached the end of their useful lives, they can be recycled, which helps reduce landfill waste.
Your Multi-Unit Residential Building
HDPE has historically been used to replace worn sewer and drain lines. In multi-unit residential buildings, it can be used as a replacement for waste stacks, soil stacks, vent lines and cold water supply lines. While PVC is a more common piping material than HDPE, you may find that some of your recently replaced pipes are HDPE, and that’s a good thing. According to research on HDPE pipes at Drexel University and reported by The Journal for Decentralized Water Treatment Solutions, HDPE is rated to last between 572 to 2,893 years. This means that barring an unforeseen disaster, HDPE pipes will outlast your residential building.
Considerations
With all the advantages high-density polyethylene pipes offer, it’s hard to believe that there would be any negatives. However, there are a few. The primary disadvantage is stress cracking. While HDPE pipes are extremely durable under most conditions, the presence of alcohol, certain detergents, and other chemicals can cause the premature breakdown of the plastic pipe.
HDPE may also leach chemicals into the potable water as it passes through the pipes. Pipe manufacturers are not necessarily required to list all of the chemicals or additives used in the creation of the pipes, and those chemicals can include UV-blockers, plasticizers, and stabilizers as well as colorants. If you are worried about the safety of your drinking water, you can have it tested, which will reveal the presence of any undesirable chemicals.
Improving the Durability and Safety of with Epoxy Liners
If you are worried about stress cracking in your HDPE pipe or chemical leaching, you may want to consider lining your pipes with epoxy. Epoxy liners are completely safe for all types of potable water pipes and drain lines, and they can improve the durability and longevity of your plumbing system.
For more information on how epoxy liners can benefit your multi-unit residential plumbing system, call us, here at Nu Flow, at 815-790-9000.