Heat Fusion Procedure
In addition to the material advantages of High Density (HDPE) Polyethylene Pipe (flexibility, corrosion resistance, light weight, etc.), the most compelling reason to choose HDPE pipe is that it provides a leak free joint that is as strong as the pipe itself and can be connected (heat fused) in a matter of minutes.
Heat Fusion Joining, Properly Done, is SAFE and SIMPLE
Heat fusion of polyethylene pipe is a just a matter of melting the ends of two piping components together. The necessary equipment uses normal electrical sources, usually from a standard generator.
The process involves cleaning the pipe, preparing the surface, heating with a designed apparatus, joining and cooling the system under pressure.
Heat Fusion Joining of PE pipe is EASY TO LEARN
PPI has developed recommended fusion procedures that have been approved by member companies, and the process has a broad range of parameters to produce good joints as documented in PPI's publication number TR-33
Inexperienced workers can be taught the basics in half an hour, and gain competence within a few hours
Equipment is widely available from distributers and contractors for sale or rental.
Training is widely available from pipe manufacturers, distributers, and equipment manufacturers.
Skilled general contractors specializing in construction and natural gas distribution systems are available nationwide.
Contact the Plastics Pipe Institute at 202-462-9607 or www.plasticpipe.org for a list of distributers.
Heat Fusion Joining is RELIABLE
Fusion joining of PE has been used for over 40 years in the distribution systems of natural gas utilities in North America, and has a remarkable safety record. In Europe, where PE pipe is often the predominant water pipe, it has been used since the 1960s. After the 1994 San Francisco earthquake, authorities were astonished at how heat-fused HDPE joints withstood the stresses created by the tremors.
HDPE Joints withstood the stresses created by the tremors.
The heat-fused joint is stronger than the pipe itself and is a leak proof method of joining water pipe
The natural gas industry has been used as a simple visual verification method for over 40 yeras to inspect joints. This process, combined with normal hydrostatic testing, has yielded an extraordinary record for both safety and efficiency.
Butt Fusion Procedure
The most widely used method for joining individual lengths of PE pipe and pipe to PE fittings is by heat fusion of the butt ends as ilustrated in Figure 1. This technique produces a permanent, economical, and flow-efficient connection. Quality butt fusion joints are produced by using trained operators and quality butt fusion machines in good condition.
The Butt Fusion Machine should be Capable of:
- Aligning the pipe ends
- Clamping the pipes
- Facing the pipe ends parallel and square to the centerline
- Heating the pipe ends
- Applying the proper fusion force
The Six Steps involved in making a Butt Fused Joint
- Clean, clamp, and align the pipe ends to be joined
- Face the pipe ends to establish clean, parallel surfaces, perpendicular to the center line
- Align the pipe interfaces
- Melt the pipe interfaces
- Join the two pipe ends together by applying the proper fusion force
- Hold under pressure until the joint is cool