Claims
- 1. A method of manufacturing a heat transfer tube, comprising the steps of:
- placing an intermediate metal layer having a low melting point around an inner tube formed of copper or steel;
- heating the intermediate layer to a temperature above its melting point to metalurgically bond it to the inner tube; and
- coating the molten intermediate layer with lead or a lead alloy while the intermediate layer is in a molten state to form an outer layer around the inner tube.
- 2. The method of claim 1, wherein the coating step is performed after heating of the intermediate layer is stopped.
- 3. The method of claim 2, wherein said step of heating the intermediate layer is performed by inserting a heater into the inner tube.
Priority Claims (3)
Number |
Date |
Country |
Kind |
58-153468[U] |
Oct 1983 |
JPX |
|
59-163419 |
Aug 1984 |
JPX |
|
59-147112[U]JPX |
Sep 1984 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 077,073,filed July 24, 1987, now abandoned, which is a continuation application of Ser. No. 846,606 filed Mar. 31, 1986, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
895412 |
Badger |
Aug 1908 |
|
4537247 |
Obamoto et al. |
Aug 1985 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
153468 |
Apr 1977 |
JPX |
152261 |
Nov 1979 |
JPX |
7311787 |
Aug 1973 |
NLX |
Continuations (2)
|
Number |
Date |
Country |
Parent |
77073 |
Jul 1987 |
|
Parent |
846606 |
Mar 1986 |
|