This article proposes a method of assessing the type and parameters of the distribution of the initial moisture content of the foam-polymer-mineral (PPM) insulation of steel pipes of underground heat pipes, as well as a method of testing the statistical hypothesis about the type and parameters of the distribution of moisture content. Investigated the possibility of reducing the amount of testing of PPM insulation steel pipe on the subject of the original moisture content without reducing the accuracy and reliability of the estimation of the true values of the original moisture content.

In this article the technique of a research of correlation dependence between initial and final moisture content of the foam-polymer-mineral (PPM) insulation of an underground heat steel pipe and also results of check of a statistical hypothesis of a type of distribution of a random variable of water absorption of PPM isolation is offered. The nature of distribution established as a result of a research speaks about existence of a limit of opportunities of PPM isolation of a pipe for water absorption – isolation with low initial moisture content is capable to absorb in itself more moisture and vice versa. Absorption of moisture happens until the value of final moisture content of PPM isolation does not reach extremely possible value approximately identical on all volume of isolation.