API5L X65 PSL2 + PWHT
API5L X65 PSL2 + PWHT
(OP)
I am buying API 5L X65 PSL2 plates 39mm thk. We asked for normalized plates but the mill says that this cannot be possible becouse the plates sour resistance will be lost with the normalizing temperature (about 600°C).
They propose TMCP plates without possibility of PWHT.
I need the plates for welded pipes according B31.3 and I need to perform two PWHT's at 593-605°C (one during the pipe fabrication and one during the site erection.
How do you think I have to procede?
Thank you for your co-operation
They propose TMCP plates without possibility of PWHT.
I need the plates for welded pipes according B31.3 and I need to perform two PWHT's at 593-605°C (one during the pipe fabrication and one during the site erection.
How do you think I have to procede?
Thank you for your co-operation





RE: API5L X65 PSL2 + PWHT
The proposed alternative by the mill is actually plate specified to ASME SA 841 - "Standard Specification for Steel Plates for Pressure Vessels, produced by Thermo-mechanical Control Process (TMCP)". I would recommend you review this specification because it requires mention of PWHT requirements in the purchase order to the mill because test coupons must be produced to simulate post forming or PWHT conditions to assure properties are not degraded. The maximum specified PWHT temperature for TMCP plate is 1200 deg F.
If the mill is proposing to substitute the TMCP plate to avoid PWHT, this is not a correct assumption for your application. The PWHT will need to be performed for plate thickness in excess of 3/4" (19mm) in accordance with ASME B31.3 for S-No 1 material (API 5L X65).
I would proceed with using API 5L X65 material and after welding perform a normalize and temper post weld heat treatment.
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
I would like to clarify our position.
We have to manufacture welded pipes for sour service starting from plates API5l X65. They are 48" and 39mm thk.
The client specification requires as design code ASME B31.3.
Now, the steel mill can supply TMCP plates only. They state that normalized or Q&T plates loose the HIC resistance due to the high temperature of normalizing process.
They state that with TMCP plates the PWHT is not necessary or if it is mandatory the max T must be 560°C for 2min*mm.
This is a deviation to ASME 31.3.
And what happen after the second PWHT on site?
RE: API5L X65 PSL2 + PWHT
Applying a second PWHT in the field for butt welds will affect toughness and HIC resistance of the plate. However, the mill can evaluate for the second PWHT application and perform an HIC test to assure minimum properties using test coupons. This has to be discussed and agreed upon with the mill.
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
What exactly are you trying to do? Are you intending to fabricate pipe to API 5L?
RE: API5L X65 PSL2 + PWHT
What I have to do to have 2 PWHT's according B31.3?
Do you think the only way is to change material?
RE: API5L X65 PSL2 + PWHT
The plate could be supplied after welding into pipe in the quenched and tempered or normalized and tempered heat treatment condition for maximum HIC resistance. The mill can work with you regarding test coupons to evaluate HIC after field PWHT.
RE: API5L X65 PSL2 + PWHT
I will try this way, but the pipe thikness will increase with this material.
RE: API5L X65 PSL2 + PWHT
(a) "When provisions less stringent than those in para. 331 are specified, the designer must demonstrate to the owner's satisfaction the adequacy of those provisions by..."
Whereas you are the pipe manufacturer, the resposibility to demonstrate that your pipe meets API 5LX65 requirements and (Engineering)HIC requirements after manufacturing including PWHT rests with you - not the skelp manufacturer. It appears that you have no justification at this time to provide pipe meeting the Engineering requirements without additional research and testing.
Has the Owner or its Engineer specified the purchase of X65 pipe for the application?
RE: API5L X65 PSL2 + PWHT
I am not the pipe manufacturer, I am a package integrator.
I know the exceptions to basic requiremente 331.2.2, and I asked to pipe mill and steel mill to demonstrate the adequacy of the proposed material but up to now they didn't answer and it seems they don't want answer.
RE: API5L X65 PSL2 + PWHT
As metengr stated, skelp from SA-516 normalized may be required, which of course will greatly increase the wall thickness required of the pipe. A specially fabricated lower strength (X42 thru X52) pipe may also be available.
RE: API5L X65 PSL2 + PWHT
The Owner can accept the code deviations about the PWHT, but requires further information as indicated in B31.3, 331.2.2 Exceptions to Basic Requirements, as i.e.:
- thermal cycling
- flexibility stress levels
- probability of brittle fracture
- additional PQR testing
Steel and pipe mills do not provide any detail and at the moment I am in big trouble with my Client.
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
Why don't you obtain some of this material from the mill and evaluate the effects of PWHT and perform HIC resistance tests? This information will provide the necessary engineering information to review with your client. All we can do is speculate and this will serve no purpose.
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
could you please explain better where in B31.3 is indicated that the PWHT after the longitudinal weld is not required?
And what about the PWHT at 560°C for 2 min*mm (as indicated by the steel miil) for the circunferential welds during the assembly and erection.
Thank you
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT
I would qualify this PWHT and have HIC testing, which you can do via weld coupons. I would still have concerns related to HIC resistance of the proposed PWHT for this high strength material.
RE: API5L X65 PSL2 + PWHT
RE: API5L X65 PSL2 + PWHT