1.1 This specification covers welded tube of copper and various copper alloys up to 31/8 in., inclusive, in diameter, for use in surface condensers, evaporators, heat exchangers, and general engineering applications. Tubes for this application are normally made of the following coppers or copper alloys:

Copper or Copper Previously Used Type of Metal Alloy UNS No. 2 Designation C10800 ... oxygen-free, low phosphorus C12200 DHP A phosphorized, high residual phosphorus C19400 ... copper-iron alloy C23000 ... red brass C44300 ... arsenical admiralty C44400 ... antimonial admiralty C44500 ... phosphorized admiralty C68700 ... arsenical aluminum brass C70400 ... 95-5 copper-nickel C70600 ... 90-10 copper-nickel C71000 ... 80-20 copper-nickel C71500 ... 70-30 copper-nickel C71640 ... copper-nickel-iron-manganese C72200 ... ... A Designation listed in Classification B 224.

1.2 Warning-Mercury is a definite health hazard in use and disposal. (See 14.1.)

Note 1-A complete metric companion to Specification B 543 has been developed-B 543M; therefore, no metric equivalents are presented in this specification.