SELECTING A CPL

When selecting a Concrete Protection Liner, the operating conditions must first be considered to ensure that you will be working within the capabilities of the material you have chosen.

Determine operating environment and chemical conditions

It is of utmost importance for the designer to be fully acquainted with the operational requirements of the Concrete Protection Liner. The first aspect to consider is the chemical environment in which the liner must operate.

Determine operating temperature range and variance

All plastic liner designs must take into account the operating temperature of the liner, as well as temperature fluctuations.

This is done so that the correct polymers may be chosen to suit the operating temperature and the correct details are used to cope with the expansion and contraction of the liner.

Determine the extent of exposure to Ultra Violet rays

AKS is available in a range of colours. Short term protection can be provided against UV degradation for all colours, but long term protection will require the liner to be black in colour.

The incorporation of carbon black ensures the best and most economical long term UV protection for HDPE.

Select a thickness based on risk of abrasion and mechanical damage

In practice, one must take into account that thin liners are more susceptible to mechanical damage during operation and especially during construction.

AKS is available in thicknesses ranging from 2.0 to 5.0mm. Careful thickness selection will lead to a long and trouble free operating life for the liner system.

Consider the carrying capacity of a pipe or channel application

HDPE has an extremely slippery surface, which enhances the carrying capacity of pipes and channels lined with it. It is generally accepted that the Manning Coefficient of Friction for concrete is approximately 50% higher than a smooth HDPE liner.

Assistance can be provided to establish the real benefit of the low friction in operational terms.

In addition to carrying-capacity, higher velocity of the liquids flowing over this surface will reduce settlement of solids, which would otherwise narrow the cross-sectional area of the conduit.

The slippery HDPE surface minimises the adhesion of deposits to the liner and does not support the growth of algae or bacteria.