Internal Cladding of Pipeline - Different Thermal Expansion Coefficient

[McDermott1711]

Considering different thermal expansion between carbon steel and say, Inconel, how do they deal with anticipated deformation when internal surface of CS pipeline is cladding with Inconel?

 

[LittleInch]

AFAIK, they work on the basis that there is sufficient compressive stress between the two elements that in effect, the lining is "fully restrained".

Given the lining is usually very thin compared to the steel then the inner lining will move with the outer shell.

Why though, is anyone lining C Stl with Inconel? The whole point about 36% Inconel is that its COE is 10% of that C stl, but as a lining there are many other linings which have the same or very similar COE to that of C Stl. I can't see the logic here?

[EDIT] Sorry, got confused with Invar.... Is there a big difference with the COE between Inconel and C Stl??

 

[McDermott1711]

AFAIK, they work on the basis that there is sufficient compressive stress between the two elements that in effect, the lining is "fully restrained".

Given the lining is usually very thin compared to the steel then the inner lining will move with the outer shell.

Why though, is anyone lining C Stl with Inconel? The whole point about 36% Inconel is that its COE is 10% of that C stl, but as a lining there are many other linings which have the same or very similar COE to that of C Stl. I can't see the logic here?

Nickel alloy 625 is one of the cladding materials introduced in paragraph 7.4.2.1 of DNV-ST-F101.

 

[LittleInch]

I made an error. See modified post.

 

[McDermott1711]

AFAIK, they work on the basis that there is sufficient compressive stress between the two elements that in effect, the lining is "fully restrained".

Given the lining is usually very thin compared to the steel then the inner lining will move with the outer shell.

Why though, is anyone lining C Stl with Inconel? The whole point about 36% Inconel is that its COE is 10% of that C stl, but as a lining there are many other linings which have the same or very similar COE to that of C Stl. I can't see the logic here?

[EDIT] Sorry, got confused with Invar.... Is there a big difference with the COE between Inconel and C Stl??

Inconel COE

API 5L X52 coefficient of thermal expansion

 

[Krausen]

You shouldn't have to worry about it assuming proper fabrication. Most piping is internal weld overlayed instead of internal cladded (unless it's large bore). The bonding strength (which can be tested if needed) between the two materials is high enough to ignore any differential thermal COE issues (i.e. the materials are integrally bonded together).

Also, there differences btw Inconel 625 & CS thermal COEs are not terribly drastic. I usually check the table in ASME BPVC II-D for these values (although B31.3 may also have a table for these values too if I recall correctly).

 

[LittleInch]

I'm not sure about that 8.5 x 10-6 m/m/C number for API noted. Seems really quite low given most design codes state 11.6.

That paper seems to be about high temperatures and is also X80, which might skew things a bit....

 

[Compositepro]

CTE is not an issue with linings. Plastic linings are common in steel pipe. Plastics have much higher CTE than steel. On flat plate you might see some warping.

 

[McDermott1711]

CTE is not an issue with linings. Plastic linings are common in steel pipe. Plastics have much higher CTE than steel. On flat plate you might see some warping.

You mean blind flange at the end?

 

[Compositepro]

No. I'm just saying that your concerns are unfounded. There might be a concern if you were dealing with a thin sheet of metal. Bimetallic springs work this way.