Coupling for insulated piping

A coupling for insulated piping, the coupling comprising:

• first and second parts for forming the coupling;
• each of the first and second parts comprising an inner conduit portion for fluid communication with an inner tube of an insulated pipe and an outer conduit portion, the inner conduit portion and outer conduit portion forming therebetween a space for fluid communication with an insulating part of the insulated pipe;
• the inner conduit portions of the first and second parts being suitable for forming an inner region for the passage of fluid therethrough;
• each of the first and second parts comprising an interface portion including a flange for connecting the first and second parts,
• the inner conduit portion of the first part comprising a projection comprising a lower thermal expansion region having a first co-efficient of thermal expansion;
• the second part comprising a projection-receiving portion for receiving the projection of the first part, the projection-receiving portion having a second co-efficient of thermal expansion, the second co-efficient of thermal expansion being greater than the first co-efficient of thermal expansion;
• wherein the projection comprises a tip portion welded to a base portion, and directly extends from the interface portion of the first part, and projects into the projection-receiving portion of the second part;
• and,
• a first seal member disposed outward of the inner conduit portions and a second seal member disposed outward of the outer conduit portions.

A coupling for insulated piping, the coupling comprising:

• first and second parts for forming the coupling;
• each of the first and second parts comprising an inner conduit portion for fluid communication with an inner tube of an insulated pipe and an outer conduit portion, the inner conduit portion and outer conduit portion forming therebetween a space for fluid communication with an insulating part of the insulated pipe;
• the inner conduit portions of the first and second parts being suitable for forming an inner region for the passage of fluid therethrough;
• each of the first and second parts comprising a flange for connecting the first and second parts,
• the inner conduit portion of the first part comprising a projection comprising a lower thermal expansion region having a first co-efficient of thermal expansion;
• the second part comprising a projection-receiving portion for receiving the projection of the first part, the projection-receiving portion having a second co-efficient of thermal expansion, the second co-efficient of thermal expansion being greater than the first co-efficient of thermal expansion;
• and,
• wherein the first part comprises an interface region for forming an interface with a corresponding region of the second part, the interface region comprising the flange;
• wherein the projection comprises a tip portion welded to a base portion, and directly extends from the interface region of the first part;
• wherein the second part comprises an interface region for forming an interface with a corresponding region of the first part, the interface region comprising the flange;
• wherein the projection-receiving portion extends from the interface region of the second part;
• and,
• wherein the coupling comprises first and second seal-forming members.