TY JOUR TI RESEARCH OF WELDING INTO SOCKET OF POLYPROPYLENE PIPES AT LOW AMBIENT TEMPERATURES KW Polypropylene KW welding into the socket KW welded spigot-and-socket joints KW fracture stress KW strength JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Botvin, G.. AU Danzanova, E.. AU Gerasimov, A.. PY 2016 IS 1 PB Belgorod State Technological University named after V.G. Shukhov