The main pipes securing the operation of engineering systems in central heating, water supply and sewerage systems can be made of a vast network of pipes. These systems have the longest route and largest dimensions, and heat losses therefrom can lead to significant energy resource consumption increases. As a result of the weather effects, a part of the existing pipeline insulation is degraded and fails to perform its functions. Polystyrene foam is useful for pipeline solutions under direct impact of weather conditions or under the ground, because polystyrene foam is capable of protecting against water effects over the course of a long time.
All above-the-ground pipelines can be subjected to two types of effects – summer sun can heat the pipes, but winter cold can lead to severe temperature decreases. Therefore, it is necessary to use a thermal insulation material which is capable of functioning in large temperature range. Furthermore, the material must withstand prolonged precipitation effect, absorbing very little amount of water and resisting frost, because freezing water can cause cracks in the insulation material. As a result of such cracks, even more water intake will take place and finally the insulation material will stop functioning. Polystyrene foam complies with all requirements and is capable of guaranteeing energy efficiency for about 50 years and more, provided that operational requirements are followed. To guarantee long-term foam rubber durability, it is necessary to protect it against adverse UV radiation as a result of which the material can start decomposing. The coating can be made of water-based coat.
The underground pipes are placed at a certain depth and mostly uniform temperature affects such pipes regardless of their cross-section (such temperature rarely exceeds +10oC). If a pipe is placed deep enough that no freezing is possible during winters, the cold water and sewerage pipes must not be insulated, but thermal insulation is nevertheless required for hot or heating water main pipelines. There might be cases when due to a technical reason it is not possible to construct pipelines in the required depth and therefore freezing risks should be accounted for. In such an event, additional thermal insulation is required. In choosing insulation material, two important parameters must be considered in all cases – long-term load resistance and durability against long-term water effects. Polystyrene foam shells are made of highly durable material which can withstand about 2,700 kg load on 1 m2; in most of the cases, such load resistance is sufficient. Studies show that EPS material in ground rarely absorb more than 1% of humidity; such amount of water does not impact the thermal technical properties.