ABRASION RESISTANCE

Transporting solid materials by fluids (in the form of a slurry) is common in industry, mining, and in many piping systems. In most cases, the flow is kept turbulent to avoid sedimentation.

Abrasion is the result of the inner surface of the pipe wall being removed or degraded by flowing media in the pipe. The rate of abrasion for various slurries is determined by many factors such as:

• Flow rate
• Density of the particles
• Size distribution of the particles
• Hardness and angularity of the particles
• Temperature viscosity of the liquid
• Incorrect installation

Abrasion resistance is one of the most important advantages of Pexgol pipes. Pexgol’s excellent abrasion resistance is a result of the unique structure of crosslinked polyethylene, making the pipe material especially tough and resilient, and generally able to resist abrasion better than metal pipes.

The ability of the pipe material to absorb the kinetic energy of the hard particles inside the slurry and its resistance to deformation make Pexgol pipes extraordinary abrasion resistant conduits.

Unavoidable scratches in Pexgol pipes cause no damage.

Results of tests performed on pipes after being subjected to scratches as deep as 20% of the pipe wall show that no damage is caused to the pipe during intensive pressure tests. The crosslinked molecular structure accounts for the insensitivity of Pexgol pipes to scratches as well as their resistance to slow-crack growth.

The restraining action of the adjacent molecular chains of the crosslinked network absorb the energy of the “tearing” forces.

Pexgol pipes abrasion resistance was tested and approved in laboratory tests as well as in on-site conditions:

>>In South African gold mines, Pexgol pipes were installed in backfill lines, working at a very high line velocity, transferring highly abrasive material for many years without failure.

>>In Israel’s Dead Sea Works, 450mm Pexgol pipes have been installed since 1985, instead of steel pipes, which had to be replaced every year. These pipes are connected to dredgers which “harvest” the salt particles. Non-crosslinked PE pipes, which were installed in these lines, failed after a few months. Pexgol pipes have been at work since 1985, and it has not yet been necessary to replace them.

Technical test reports concerning abrasion resistance of Pexgol pipes are available on request.

Pexgol pipes have an “abrasion allowance” of 20% of the nominal wall thickness of the pipe. This means that the pipe can withstand the design working pressure until the remaining wall thickness of the pipe is reduced to 80% of the nominal value. The real lifetime of the pipe depends on the actual abrasion rate in the line. The 80% rule applies for all working pressures and all temperatures in all classes.