FIELD: machine building.
SUBSTANCE: in set of heat-hydro-insulated pipes each heat-hydro-insulated pipe of said set consists of at least one working pipe, preferably, metal, for example steel, of one layer of hydro-insulation in form of metal, preferably, steel casing or casing out of polymer or polymer-containing material and of one layer of heat insulation out of foam polyurethane. Also heat-hydro-insulated items are fabricated within working pipe diametre ranges fro 200 to 1050, mainly from 219 to 1020 mm facilitating volume protection with heat-insulating material. The procedure includes five main stages of pipe fabrication. At the first stage of fabricating the external pipe-casing polymer material is heated, extruded, formed, calibrated and the form of the pipe-casing is stabilised at vacuum three-axes expanding and simultaneous cooling. At the third stage pipes are hydro-insulated ensuring volume protection of the working pipe with hydro-insulating material for each item. Volume protection is calculated from ratio of specific volume of hydro-insulation to a unit of payload volume of arbitrary running metre of the working pipe and is not more, than 0.17. Notably, volume protection with hydro-insulation quantitatively grows with decrease of external diametre of the protected internal metal working pipe.
EFFECT: increased process simplification and efficiency of production of preliminary heat-hydro-insulated pipe; increased reliability of hydro-insulating casing; ensuring decreased heat loss during finished product operation.
19 cl, 10 dwg
