What pipe to choose for underground water supply

I connect the house to a centralized water supply. It is necessary to lay a pipe underground at a distance of 100 meters. What plastic pipe do you recommend?

Peter

Expert Answer

Peter, when choosing a pipe for an underground water supply, it is necessary to take into account the depth of its occurrence and the maximum water pressure in the system. The pressure in household water supply lines does not exceed 6 atm, and this allows the use of both polyethylene and polypropylene pipes. The former are designed for operating pressures up to 10 atm, and the latter are even more so.

As for the depth of laying the pipeline, according to SNiP, the main line for cold water supply is laid at a depth of 0.5 m below the freezing point of the soil. And if in the southern regions a layer of soil up to one meter thick will exert pressure on the pipe, then in the northern latitudes this parameter will more than double.

Therefore, in the first case, it is possible to lay communications with a low-pressure polyethylene pipe (HDPE), for example, PN10. For drinking water, you should choose blue pipes (or black pipes with a longitudinal blue stripe) - they do not affect its properties at all. For cold areas, as well as areas with stony soil, it is better to use polypropylene (PP) - it can withstand soil pressure several times higher than HDPE.

Since pipes made of low-pressure polyethylene do not tolerate cold, they must be insulated, even if we are talking about an underground highway. The same is recommended for polypropylene water pipes. So you will protect the pipes from changes in the structure of the material at temperatures below zero, and you will not worry about freezing the water supply system in the most severe frosts.