Please, help me find some information about thermal networks in English. I need reliable information for my project and exactly in English. I have found some, but it was incorrect.

Only on paid platforms you can find this kind of information. Just find the right site that provides all sorts of information in English. I do not think that it will cost much.

Look at here sp 124.13330.2012 in English https://gostperevod.com/sp-124-13330-2012.html.  Hope it is what you are searching for. The information like this hard to find, that’s why I like this website, because there I can find whatever I need. Also, the service in a high level. They will help you, even if they do not have it. They have a different set of rules.