API 5L expansion ratio

[zebmahar]

It is written in API 5L, 44th edition Page No. 21

8.9 Cold Sizing and Cold Expansion

8.9.1 Except as allowed by 8.9.2, the sizing ratio for cold sized pipe shall not be more than 0,015, unless
(a) the pipe is subsequently normalized or quenched and tempered, or
(b) the entire part of the pipe that is cold sized is subsequently stress relieved.

8.9.2 Unless otherwise agreed, the sizing ratio for cold expanded pipe shall not be less than 0,003 or more than 0,015.


Please tell me, either this clause allows expansion more than 0,015 when subsequent heat treatment (normalizing) is performed, or heat treatment (normalizing) shall be performed when expansion ratio reaches 0,015

Hoping for prompt replies form u guys

Kind regards
Zebmahar

 

[Duwe6]

Zebmahar, these clauses make sense in english, may have lost something in translation:

8.9.2 -- Cold expanded pipe is to be expanded to a ratio of; greater than 0.003; and less than or equal to 0.015 [without subsequent heat treatment]

8.9.1 -- Cold expanded pipe that is heat treated after expanding is allowed to exceed a ratio of 0.015. Heat treatment may be either "Normalizing" or "Quenched & Tempered"; or stress relieved -- "PWHT", with the expanded area heat-treated instead of a weld being heat-treated.

Thus, up to and including a ratio of 0.015 does not require heat treatment. Greater than 0.015 does.

 

[zebmahar]

Duwe6, Thanks for your reply

It means we can expand the pipe OD up to a ratio of 5.0 followed by heat treatment, would it be ok?

Hoping for quick reply

Best regards

 

[Duwe6]

That is indeed how I read it. Obviously, watch your wall thickness, and watch for cracking/ruptures.

 

[zebmahar]

Thanks again