US 9,810,366 B2
High temperature field joints
Jan Peder Hegdal, Fannrem (NO); Torgeir Sletvold, Orkanger (NO); Eileen Wan, Richmond Hill (CA); and Suresh Choudhary, Houston, TX (US)
Assigned to SHAWCOR LTD., Toronto (CA)
Filed by ShawCor Ltd., Toronto (CA)
Filed on Aug. 8, 2014, as Appl. No. 14/455,213.
Claims priority of provisional application 61/863,976, filed on Aug. 9, 2013.
Claims priority of provisional application 62/021,751, filed on Jul. 8, 2014.
Prior Publication US 2015/0041017 A1, Feb. 12, 2015
This patent is subject to a terminal disclaimer.
Int. Cl. F16L 9/14 (2006.01); F16L 59/02 (2006.01); B23K 31/02 (2006.01); B23K 37/00 (2006.01); F16L 58/10 (2006.01); F16L 59/14 (2006.01); F16L 58/18 (2006.01); F16L 59/20 (2006.01); F16L 13/02 (2006.01); B29C 39/10 (2006.01); B29C 33/00 (2006.01); F16L 1/16 (2006.01); F16L 9/02 (2006.01); F16L 9/22 (2006.01)
CPC F16L 59/029 (2013.01) [B23K 31/02 (2013.01); B23K 31/027 (2013.01); B23K 37/00 (2013.01); B29C 33/0011 (2013.01); B29C 39/10 (2013.01); F16L 1/161 (2013.01); F16L 9/02 (2013.01); F16L 9/22 (2013.01); F16L 13/0272 (2013.01); F16L 58/1054 (2013.01); F16L 58/1081 (2013.01); F16L 58/181 (2013.01); F16L 59/14 (2013.01); F16L 59/143 (2013.01); F16L 59/20 (2013.01)] 43 Claims
OG exemplary drawing
 
1. A method for forming a field joint between two insulated pipe sections, the method comprising:
(a) providing a first insulated pipe section and a second insulated pipe section, wherein each of the insulated pipe sections comprises:
(i) a steel pipe having an outer surface and an end, wherein an annular connection surface is located at said end of the steel pipe,
(ii) a corrosion protection coating provided over the outer surface of the steel pipe, wherein a terminal end of the corrosion protection coating is spaced from the end of the pipe; and
(iii) a pipe insulation layer provided over the corrosion protection coating, wherein a terminal end of the pipe insulation layer is spaced from the end of the pipe, and wherein the pipe insulation layer comprises a polymer composition having thermal conductivity of less than about 0.40 W/mk, and/or heat resistance to continuous operating temperatures from about 150° C. to above about 205° C.;
wherein the corrosion protection coating and the pipe insulation layer together comprise a line pipe coating of the insulated pipe sections; and
wherein each of the insulated pipe sections has a bare end portion in which the outer surface of the steel pipe is exposed, the bare end portion extending from the end of the steel pipe to the terminal end of either the corrosion protection coating or the pipe insulation layer;
(b) welding the steel pipe of the first insulated pipe section to the steel pipe of the second insulated pipe section, so as to form a circumferential weld joint between the annular connection surfaces of the steel pipes, and so as to form a continuous joint area which includes the circumferential weld joint and the bare end portions of the insulated pipe sections;
(c) applying a first field joint insulation layer over the joint area, wherein the first field joint insulation layer comprises a polymer composition having heat resistance to continuous operating temperatures from about 150° C. to above about 205° C.