Refrigerant hose and method of manufacturing same

A method of manufacturing a refrigerant hose through which a refrigerant of an air conditioner installed in a vehicle flows by sequentially and coaxially layering an inner surface layer, a reinforcing layer composed of a reinforcing cord, and an outer surface layer to mold a hose molded article and vulcanizing the hose molded article, the method comprising:

• making a plurality of specifications of a fiber cord having an outer diameter of 0.4 mm or more and 0.6 mm or less different;
• vulcanizing a sample of the hose molded article molded by using the fiber cord of each of the specifications, then performing tensile testing on each fiber cord removed from the sample at 150° C. to grasp a relationship between a tensile load and elongation in advance, and performing tensile testing on each fiber cord at room temperature to grasp strength at break;
• based on respective standard values of elongation under a load of 1.3 cN/dtex at 150° C. and strength at break at room temperature that are required for the reinforcing cord of the refrigerant hose and based on the relationship grasped in advance and the strength at break, determining a specification of the fiber cord before vulcanization that satisfies the respective standard values;
• and
• molding the hose molded article by using, as the reinforcing cord, the fiber cord having the specification determined.