A53

Date 07-26-2008 16:55

When I have ordered "black" pipe before, it usually comes with a clear laquer rust-preventative coating. Nothing that would be considered long term corrosion protection.

By G.S.Crisi (****)

Date 07-26-2008 22:50

The word "black" is there because many years ago (say 40 years or more) the finishing coating was a hand of a tar based rust preventing paint. As tar is black, the finishing color was also black. Nowadays, as G. Roberts says, there are more modern coatings, but the word black is still there.
Hot dip galvanized means that the just rolled (or extruded) pipe is submerged for a few seconds into a bath of molten zinc.
They're two different finishings, hot dip galvanized being the more expensive, of course.
Giovanni S. Crisi
Sao Paulo - Brazil

By weber

Date 07-28-2008 19:47

Gentleman
Thank you very much for your reply.
The base of the question is coming from one of my friend's mind. He has some shortage of A106 grade B in his project. He asked my idea about replacement of A106 grade B with seamless A53 grade B, which is exist in the project. I compared these two materials and it seems they are same except the coating of the A53. Am I right about that?

By 803056

Date 07-29-2008 16:28

The A106 contains both carbon and manganese as alloying constituents. The A106 is better for higher temperature applications than A53 which is more prone to graphitization if held at high temperature for a long period of time. So, they are not the same and A53 should not be used as a substitute unless the engineer has been consulted. The A53 may be adequate for an ambient temperature application, but again, you have to know the particulars before making the substitution.

Best regards - Al