Influence of temperature and time modes of polymer pipes welding at low temperatures on the structure and properties of materials of compounds. Part I. Calculation of the heat process

Subject of research: thermal process welding PE100 saddle branches to polyethylene pipes existing gas pipelines at low temperatures.
 Purpose development an effective method for ambient temperatures up minus 50 C based on control by introducing preheating into the technological with subsequent cooling equalize temperature and cool joint under a layer insulation material calculated thickness.
 Methods objects in first part work, object study is non-stationary welding. The mathematical model takes account heat phase transformation range, dependence thermophysical characteristics degree crystallinity material.
 Main results calculations have determined parameters branch, which ensure flow according regularity inherent conditions permissible temperature. It expected that will make it possible obtain structure welded ensures strength seam corresponding obtained acceptable temperatures.