Is HDPE Pipe Better than PVC?

Recently, leading power plants have been quietly turning to high-density polyethylene (HDPE) - a highly durable, corrosion-resistant piping option that can dramatically improve hydraulic efficiency. While HDPE is becoming more widely used, the vast majority of steam generating stations are still using outdated transmission piping, leading to an increase in pipe-related failures and plant shutdowns.

What is a typical use case for HDPE?

HDPE is a thermoplastic pipe, made from petroleum, that is completely corrosion resistant. Because it is strong enough to withstand applications above or below ground or in water, HDPE is used in a variety of applications such as mining, chemical/petrochemical and other process-related industries. The use of HDPE rather than PVC in the power industry is increasing due to the large volumes of water that must be treated, refined and recycled in a typical production cycle. Specifically, HDPE pipe is used to transport ultra-pure cooling tower water, one of the most critical systems in the power generation process. Since power plants cannot operate without pure water, having a reliable piping system that can handle the process requirements is a top priority for operators.

HDPE Pipe

Does HDPE have a longer service life?

HDPE far outlasts PVC in terms of service life. industry reports indicate that PVC has an installed life of 8 to 15 years. Over the years, PVC piping has changed dramatically. It becomes brittle and therefore more prone to cracking or breaking when there are pressure fluctuations in the system. Some plant leaders even recommend scheduling replacements every five years to ensure that operations are not affected by PVC degradation.

HDPE pipe, by contrast, lasts 50 to 100 years and hardly degrades over time. It is also more flexible, making it much less sensitive to pressure fluctuations. In addition, HDPE does not rust or rot, allowing the pipe to remain intact longer.

In fact, according to the Plastic Pipe Institute (PPI), HDPE piping has the lowest life-cycle costs compared to other systems because it has significantly fewer or no leaks, saves water, reduces new water treatment plants, reduces maintenance staff, reduces seasonal water main breaks, and has no loss of flow capacity over time.

HDPE Mining Tailing Pipe

How does installation differ from PVC?

PVC plumbing products use water-resistant glue to connect individual pipe sections. This glue takes 8 to 10 hours to dry, whether for repairs or a brand new installation, or longer if testing is required before resuming operations.

High-density polyethylene pipes are joined by hot fusion, and once joined, a leak-free pressure rating is achieved in just eight minutes. During the fusion process (as reported by PPI), matched pipe ends are aligned and heated with a standard tool until the surface is melted.

When joined at moderate pressure, the molten surfaces flow together to form an integral, uniform joint, producing a joint that is as strong or stronger than the pipe itself as the material cools. There are several other well-established hot melt procedures for joining HDPE pipe, including electrofusion (particularly suitable for assembling pipe to fittings or for making connections or repairs) and saddle fusion (for attaching service fittings to HDPE mains).

In addition, many users experience significant cost savings during installation as HDPE is lighter but more flexible like PVC. HDPE can also be installed using trenchless technology, which is the most efficient method.

The source is from here.