ASTM A106 section 4.4 1

[Genetix]

Hi everyone,

Im currently studying ASTM A 106 specifications. On section 4.4 it is specified that "Unless otherwise specified, pipe NPS 2 [DN 50] and over shall be furnished hot finished. When agreed upon between the manufacturer and the purchaser, it is permissible to furnish cold-drawn pipe"

Based on the above information by specs, I think it is safe to say that most of A106 pipes with NPS 2 [DN 50] and above is hot finished and cold-drawn pipe of NPS 2 [DN 50] and above is seldom used. I just want to know why most are hot finished. What's in it in cold-drawn A106 pipes that needs manufacturer and the purchaser approval.

Thanks.

 

[granQC]

Hello!

Yes, as per the standard, cold-drawn method for smaller pipe (D<2") can be conducted.
I think the main reason of this is that these line sizes, D<2", are mainly used in utility lines (non-critical/process service) therefore reduced yield strength and hardness by plastic deformation (cold-drawn) is not that significant.
However, for sizes D>=2", which is used for process fluid/service, mainly these two mechanical properties is essential and of great factor to maintain.

Remarks: Maybe that is why, D>=2" and above was required by ASTM to be heat treated after cold-drawn to improve the property.

Better consult with experts.

Ciao!

 

[metengr]

For cold drawn over a mandrel it boils down to surface finish requirements, holding dimensional tolerances and cost.