Hose, hose assembly, and manufacture method

An ultrahigh-pressure acid-fracturing isodiametric hose assembly, comprising a hose body and a metal joint, wherein:

• the metal joint comprises an inner tube, a first outer tube which is configured to serve as a sleeve outside the inner tube, a second outer tube which is configured to serve as a sleeve outside an outer wall of the first outer tube, and a threaded ring configured to be connected with a terminal of the inner tube via a thread;
• the first outer tube is capable to press against the inner tube independently, and the second outer tube is capable to press against the outer wall of the first outer tube independently;
• an external groove for snapping is provided at an outer wall of the threaded ring;
• an end of the first outer tube comprises an internal ridge for snapping which matches the external groove for snapping;
• the terminal of the inner tube comprises a connecting portion;
• an outer wall of the inner tube comprises a first protrusion, and an inner wall of the first outer tube comprises a second protrusion configured to engage with the first protrusion;
• the hose body when connecting with the metal joint is clamped between the first protrusion and the second protrusion that are engaged;
• and
• an inner wall of the second outer tube comprises micro-protrusions;
• an inner wall of the hose body comprises a hose inner layer, and an outer wall of the hose body comprises a hose outer layer;
• the hose body comprises an ultrahigh-molecular-weight wear-resistant inner lining layer, an inner rubber protective layer, a first intermediate rubber layer, an inner fiber-fabric layer, a second intermediate rubber layer, a skeleton layer, a twelfth intermediate rubber layer, an outer fiber-fabric layer, and an outer rubber protective layer which are arranged from inside to outside;
• the skeleton layer of the hose body comprises steel-wire winding layers which are sequentially arranged along a radical direction of the hose body;
• an innermost one of the steel-wire winding layers is a steel-wire winding layer having a sequential number of 1;
• a winding angle of a steal wire in each steel-wire winding layer with an odd sequential number is α, and α ranges from 53.0 degrees to 54.0 degrees;
• and
• a periodical length of a steel wire in one of the steel-wire winding layers which has a sequential number of n is identical to a periodical length of a steel wire in another of the steel-wire winding layers which has a sequential number of n−1, when n is an even number.