US 11,808,532 B2
Highly corrosion-resistant copper tube
Kozo Kawano, Nagoya (JP); and Shinobu Suzuki, Nagoya (JP)
Assigned to NJT Copper Tube Corporation, Aichi (JP)
Filed by NJT Copper Tube Corporation, Toyokawa (JP)
Filed on Jan. 20, 2021, as Appl. No. 17/153,171.
Application 16/129,209 is a division of application No. 14/849,955, filed on Sep. 10, 2015, abandoned.
Application 17/153,171 is a continuation of application No. 16/129,209, filed on Sep. 12, 2018, abandoned.
Application 14/849,955 is a continuation of application No. PCT/JP2014/052418, filed on Feb. 3, 2014.
Claims priority of application No. 2013-055963 (JP), filed on Mar. 19, 2013.
Prior Publication US 2021/0140727 A1, May 13, 2021
Int. Cl. F28F 1/00 (2006.01); F28F 21/08 (2006.01); F28F 19/00 (2006.01); C22C 9/00 (2006.01)
CPC F28F 21/085 (2013.01) [C22C 9/00 (2013.01); F28F 1/00 (2013.01); F28F 19/00 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for suppressing ants' nest corrosion, comprising:
producing a heat transfer tube, wherein the heat transfer tube consists of copper, phosphorous, and inevitable impurities comprising at least one of Fe, Pb, and Sn, the inevitable impurities being contained in an amount of not higher than 0.05% by weight in total, and the producing of the heat transfer tube includes adding the phosphorous so as to be 0.19-1.0% by weight in total to suppress the ants' nest corrosion,
positioning the heat transfer tube in air-conditioning equipment and operating the air-conditioning equipment, whereby the heat transfer tube is exposed to a corrosive action caused by a corrosive medium comprising at least one lower carboxylic acid, in which said corrosive action progresses in the form of said ants' nest corrosion from an outer surface of the heat transfer tube in a direction of its wall thickness.