Technical data

Examples of Incorrect Electrofusion Joints
PIPE UNDER-SCRAPED
The visible tool marks show that some effort was made to scrape the
pipe. Unfortunately there was not enough material removed to allow a
proper fusion. While most of the fitting did not fuse to the pipe, a small
section did. When the joint failed, the stress on the section that did fuse
was too great, causing the coupling to break.
PIPE MIS-STAB
The combination of a crooked cut on the end of the pipe, and the pipe
ends not being centered in the pipe, have created a condition known as a
Mis-stab or a short-stab. When this occurs the pipe does not create a
adequate seal in the center cold zone. This causes molten material to
flow toward the center of the fitting. The loss of material and pressure at
the joint interface result in poor joint integrity.
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