Specification determination method of fiber reinforced member for marine hose and method of producing marine hose

A specification determination method of a fiber reinforced member having a cord fabric structure used as a reinforcing layer of a marine hose, the fiber reinforced member comprising fiber cords arranged in parallel and a transverse cord transversing the fiber cords so as to weave the fiber cords, the specification determination method, comprising:

• setting a twist coefficient K of the fiber cords calculated by a following formula (1) to 1900 or more and 2900 or less with a specification of the fiber cords in which three or four filaments made of polyester are twisted,
• twist coefficient K=T×D1/2 . . . (1), in which
• T is a secondary cable twist count of the fiber cords (count/10 cm) and D is a total fineness of fiber cord (dtex);
• grasping an interrelationship between a predetermined elongation ratio of a plurality of types of the fiber cords having different specifications and a hose elongation ratio in a predetermined expansion test of each marine hoses in which the fiber reinforced member comprising the respective fiber cords as constituent members is embedded as the reinforcing layer in advance by previously performing the predetermined expansion test in relation to a plurality of marine hoses including different fiber reinforced members respectively formed using plurality of types of the fibers cords having the different specifications;
• setting a threshold of the predetermined elongation ratio based on a standard value of the hose elongation ratio in the predetermined expansion test required for the marine hose and the interrelationship;
• and
• setting the predetermined elongation ratio of the fiber cords used as the reinforcing layer to the threshold or less.