It is the intrinsic stiffness of the pipe which makes it suitable for underground applications, where the pipe is subjected, not only to internal pressures, but continuous external loading
There is now a general acceptance of the use of plastic pipe for transporting a wide range of products, such as water, oils, gases etc It has successfully replaced conventional materials such as steel, copper, lead and cast iron, and has many advantages, but it is not without problems.
One serious problem, particularly for underground applications, is brittle cracking due to incorrect use of material, ageing, and land movement etc This type of failure is said to have been responsible for some major accidents in the past, but new materials and better testing procedures are helping to overcome the problem.
It is therefore essential that at both the design and production stages, the ring stiffness of the pipe is measured.
Testometric has developed a range of machines that will automatically calculate the ring stiffness of the pipe sections up to 1800mm diameter.
They can also be configured to conduct cyclic tests over a specified period to simulate the creep effect of long term loading and the effect of varying loads that could be caused by land movement and other forces the pipe may be subjected to.
The machines are fully universal and can also be used for testing the tensile strength of the pipe material to check the integrity of the welded joints. Machines are available with capacities from 5 to 300kN.
