How is HDPE pipe effectively fused to other materials?

In the utilities industry, the joining of high-density polyethylene (HDPE) pipes is an important part of installation and maintenance. Although HDPE glues have become fairly common, there are several other methods of fusing lengths of HDPE piping to other materials and to each other. Let’s take a look at the various fusion methods and their comparative merits.   

Various fusion techniques

For many years, the standard way of fusing HDPE pipe has been welding. There are two ways in which this can be done: butt welding and electrofusion.

Butt welding is the most common method. This is a thermofusion process in which the ends of two pipes or fitting components are heated simultaneously until each contact surface reaches a molten state. They are then brought together under controlled pressure so that the two molten ends meet, cool and form a permanent joint. The resulting joint has remarkable load-bearing capacity and performs extremely well under pressure.

Electrofusion is used when butt welding is not possible, especially where valves, fittings, and elbows must be installed. Prefabricated fittings are used that incorporate electrical heating coils which melt the plastic of both pieces to be joined, causing them to fuse together.

Mechanical assembly is also a common method, involving no welding at all and depending instead on the compression principle to join different elements together. It most commonly used in cases where fusion is not feasible, such as where HDPE pipe is to be joined to a fitting made from a different material. Mechanical fittings include a stiffener which is placed inside the pipe to ensure stability. They also include gaskets, which are compressed to create the seal that holds the two ends of pipe or fittings together.   

HDPE glue

As effective as these methods are, there is a far easier way to create strong, lasting bonds between HDPE pipe and fittings of other material. HDPE glues of various types are now commonly used in the installation of HDPE pipe. While some doubt the ability of glue to form the kind of bond that underground pipelines need to operate under pressure, quality HDPE glues have been shown to work just as effectively as welding and mechanical assembly, and they are much quicker and easier to apply.

GRA Services, a trusted supplier to utility companies throughout the United States, has formulated an HDPE adhesive that is rapidly becoming the industry standard. PE Fusion is a high-strength modified acrylic adhesive designed for the coupling and splicing of HDPE pipe to standard PVC couplings as well as other non-standard materials such as aluminum, steel and fiberglass. It securely bonds all surfaces and is ideal for splicing underground utilities, creating a watertight bond and allowing flexibility in conduit selection and installation. It is far more cost-effective than mechanical couplings and lasts longer too. PE Fusion’s acrylic formula has proven to be far superior to other formulations - mostly epoxies that require mechanical bonds and are vulnerable to impact stress.

If you are seeking the best HDPE glue for your pipelines, look no further than PE Fusion. Contact GRA Services for more information on this and other products.