Advantages

Tensile Strength

The tensile strength required can be calculated on the basis of pipe weight. In addition to the pipe weight, gravel that gets stuck in the joints during the assembly and settlement phase should be considered in design calculations. The lower load bearing capacity of screen pipes with slots should be considered when developing the well or when pumping (due to large differences in water level). The effect of such pressures cannot be precisely determined. When sinking pipes through clay layers, additional compressive forces are exerted due to swelling clays. This can happen at any depth and in extreme cases may cause considerable strain on the material surface. The values indicated in the tables of this brochure are based on the minimum wall thickness of the pipes, their diameters and material composition.

Impact of Temperature

Temperature conditions prevailing during the laying of PVC-U well pipes will influence the mechanical properties of the material. High temperature between 30° C and 40° C as indicated by the creep strength in relation to time, the PVC-U material properties provide sufficient safety factor for the intended use. It is however important to determine the other influences while encasing the well pipes with concrete to seal the drill holes. Temperature increases can be caused by the hydration heat of concrete. Calculations however show that these temperatures do not normally exceed 15°C. With the temperature of unset concrete reaching approx. 18°C, the temperature within the seal will be slightly more than 30°C and that is within the optimum limits.

Application

Specification

Materials

PVC-U, unplasticised polyvinyl chloride is an ideal material for manufacturing well pipes as it is

impervious to corrosion and chemical action, easy to handle and install, light in weight, non-toxic,

and non-conductive. Its long service life makes it an economical choice over other materials.

Production