Title:
METAL PIPE HAVING INNER PROTECTIVE TUBE AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2017/135621
Kind Code:
A3
Abstract:
The present invention relates to a metal pipe having an inner protective tube and a manufacturing method therefor, in which the inner protective tube capable of enhancing corrosion resistance and wear resistance is inserted into the metal pipe to increase the lifespan of the metal pipe and to prevent a material transported through the metal pipe from being contaminated due to corrosion. The method according to the present invention for manufacturing the metal pipe having the inner protective tube comprises: a step for inserting the inner protective tube into a pipe main body, the inner protective tube having an outer diameter smaller than the inner diameter of the pipe main body; a step for inserting a tube-expanding unit into the inner protective tube; a tube-expanding step for expanding the inner protective tube toward the outside through the tube-expanding unit, which has been inserted in the inner protective tube, to allow the outer circumferential surface of the inner protective tube to make contact with the inner circumferential surface of the pipe main body so that the inner protective tube and the pipe main body are coupled with each other; and a pipe-heating step for heating part of the pipe main body in which the inner protective tube is to be expanded, in order to increase the inner diameter of the pipe main body by a predetermined value after the inner protective tube is inserted into the pipe main body.
Inventors:
KIM SUNG-SIK (KR)
Application Number:
PCT/KR2017/000790
Publication Date:
August 02, 2018
Filing Date:
January 24, 2017
Export Citation:
Assignee:
KIM SUNG SIK (KR)
International Classes:
F16L9/18; B21D39/04; B21D39/08; B21D39/10; B21D41/02; F16L9/19; F16L57/06; F16L58/04; F16L58/08
Domestic Patent References:
| WO2014169367A2 | 2014-10-23 |
Foreign References:
| JPH07284844A | 1995-10-31 | |||
| KR100963423B1 | 2010-06-15 | |||
| US4538337A | 1985-09-03 | |||
| JPH11290939A | 1999-10-26 |
Attorney, Agent or Firm:
G1 IP LAW FIRM (KR)
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