TWI Industrial Member Report Summary 647/1998
F A Hinchcliff and M J Troughton
Various short-term coupon tests have been assessed regarding their ability to discriminate between welds made using different welding conditions.
Plastics are increasingly being used for high integrity structural components. One example of this is the use of welded polyethylene pipe systems for the distribution of pressurised water and gas. Since such systems contain a large number of welds, there is a need for reliable standard procedures to evaluate the mechanical properties of these joints.
There are currently a large number of different short-term coupon tests for assessing the quality of welded joints in thermoplastics. To date, however, very little work has been performed to correlate results from one test with those from another.
To establish which of the short-term coupon tests currently used in the plastics pipes industry are able to discriminate between butt fusion joints in large diameter polyethylene pipes, made under very different welding conditions.