Abstract: Use of a heat transfer tube in a damp environment in air-conditioning equipment and exposed to corrosive action caused by a corrosive medium comprising at least one lower carboxylic acid, the heat transfer tube a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities. The corrosive action progresses in the form of an ants' nest from an outer surface of the heat transfer tube in a direction of its wall thickness, wherein. Also, use of a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities for improving corrosion-resistance against ant nest corrosion caused by a corrosive medium consisting of a lower carboxylic acid in a damp environment, method of inhibiting ants' nest corrosion in a heat transfer tube, and a method of positioning a tube in an air conditioning apparatus or a refrigeration apparatus.

Abstract: Provided are a mechanical tube fitting for preventing bending fracture of a tube member to be joined when subjected to bending deformation, and a simple tube fitting structure including that tube fitting. In the tube fitting, a clearance between a tube member (32) to be joined and an outer pipe (12) or an inner pipe (14) which is coaxially inserted in the outer pipe (12) and gives a space between its outer surface and the inner surface of the outer pipe (12), in which space the tube member (32) is inserted, is sealed with a sealing member disposed between the outer pipe (12) and the inner pipe (14), and the above-mentioned components are fixed by caulking. The outer pipe (12) is configured to extend outwardly in its axial direction than the ends of the inner pipe (14).

Abstract: Use of a heat transfer tube in a damp environment in air-conditioning equipment and exposed to corrosive action caused by a corrosive medium comprising at least one lower carboxylic acid, the heat transfer tube a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities. The corrosive action progresses in the form of an ants' nest from an outer surface of the heat transfer tube in a direction of its wall thickness, wherein. Also, use of a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities for improving corrosion-resistance against ant nest corrosion caused by a corrosive medium consisting of a lower carboxylic acid in a damp environment, method of inhibiting ants' nest corrosion in a heat transfer tube, and a method of positioning a tube in an air conditioning apparatus or a refrigeration apparatus.