The article discusses the comparison of polyethylene and steel pipelines. The definition of coefficient of temperature linear expansion for polyethylene pipelines is given. The analysis of existing methods to determine the linear dimensions of compensators and their compensating ability was carried out. The analysis of the obtained dependences showed that the calculated compensating ability, in some cases, exceeds the geometric dimensions of the compensator. The method for determining the compensating ability is determined.

Keywords: coefficient of temperature linear expansion, linear size of the compensator, polyethylene pipe, compensating ability