Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

PQR Preheating

Status
Not open for further replies.

PipinFool

Petroleum
Joined
Jul 24, 2006
Messages
9
Location
US
I am in the process of establising some new PQR's under API 1104 code, section 5.
The pipe grades to be tested will be the norm for the pipeline industry:

X-42, X-60, X-65 and X-70

Weld Processes to be used:

SMAW cellulose electrode
SMAW cellulose + lo-hy electrode
GMAW
FCAW

My question is, how do I determine what should be preheated?

I planned on determining hardness values in the HAZ. I have conflicting information as to what HV values I should shoot for.

Should I be looking at other alternatives?

Any information whould be greatly appreciated.

Thank you.



 
Preheat per 7.11 & 5.4.2.14 of API 1104 will depend on metallurgy (CE) of base material and deposited weld metal, thickness of base metal and atmospheric conditions. If you have hardness requirements, preheat must also be adressed. As CE and thickness increase and as ambient temp and hardness requirements decrease, the preheat temp must increase to mitigate cold cracking decrease hardness.

 
Oops. 5.4.2.14 should be 5.4.2.13. Also refer to 5.3.2.13.

 
If this is a sour service then unless the end user has some more stringent requirements, I would look to NACE MR0175/ISO 15156 for guidance on the hardness testing required in the weld procedure qualification and for the acceptance criteria.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top