B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
B21C37/00—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
B21C37/06—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
B21C37/15—Making tubes of special shape; Making tube fittings
B21C37/20—Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies ; Making tubes with angled walls, ribbed tubes or tubes with decorated walls
B21C37/205—Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies ; Making tubes with angled walls, ribbed tubes or tubes with decorated walls with annular guides
Landscapes
Engineering & Computer Science
(AREA)
Mechanical Engineering
(AREA)
Shaping Of Tube Ends By Bending Or Straightening
(AREA)
Procede pour la fabrication d'une surface de chauffe d'une chaudiere exempte de condensation d'eau, composee d'une enveloppe interieure et d'une enveloppe exterieure, et surface de chauffe fabriquee par ce procede
Serpentin tubulaire a deux etages d'enroulements en spirale, echangeur de chaleur mettant en oeuvre un tel serpentin et procede de fabrication du serpentin