Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Hardness Test after PWHT

Hardness Test after PWHT

Hardness Test after PWHT

I have to send all the BW joint CS/SS pipes (thickness is less than 3/4") for PWHT. The code says PWHT is not required if the thickness is below 3/4", but it's client requirement so have to do it.
Can anyone tell me how much hardness is required for testing? the services are Sour Gas and Amine.

RE: Hardness Test after PWHT

Each material Hardness is determined. When you PWHT it The effect on hardness and the hardness depends on the cooling rate.
When you PWHT it, you must check the hardness to make sure it is in the correct.

RE: Hardness Test after PWHT

In my experience Amine service usually follows NACE MR0103, which mandates SP0472. SP0472 states weld deposit hardness shall be controlled to 200HBW. There are exemptions to production hardness testing in SP0472, but if you are definitely hardness testing CS welds, that's what you should be below.

RE: Hardness Test after PWHT

Forgot to mention that newer editions of piping codes (B31.1/B31.3) no longer have mandatory PWHT for P1 materials....as long as you preheat to 200F if thickness is over 1".

RE: Hardness Test after PWHT

David, does SP0472 states that the welds have to go for hardness test even though the thickness of the pipe is less than 3/4"?

RE: Hardness Test after PWHT

Why don't you ask the client for this information? If they are requiring it they should have this information.

RE: Hardness Test after PWHT

We have PWHT requirement stating 1150F for 60 mins. Is there a typical cycle for PWHT in code with rising and falling rates which have to be followed while heat treating? something like
"Ambient to 600F at moderate rate
600F to 1150F at 400F/ hour
Hold 1150F +/- 25F for 60 mins
Cool to 600F at 400F/hr"

RE: Hardness Test after PWHT

sorry didn't mention earlier, the material is Carbon Steel SA-106 Gr.B

RE: Hardness Test after PWHT

Several of the ASME piping codes contain requirements for heating and cooling ramp rates based on pipe wall thickness. Please refer to your code of construction.

RE: Hardness Test after PWHT

For reference, the PWHT requirement for the CS (P1) piping may be based on the pipe thickness per AMSE B31.3, i.e. >3/4" WT (2012 or earlier) or >1" WT (2014 or later), or depended on the services condition which may apply to all pipe thicknesses, such as Amine, caustic, Carbonate, Anhydrous Ammonia services, etc. You may want to confirm with the Client for a specific Code as required to be followed.

RE: Hardness Test after PWHT

metengr is rigth, those who ask for PWHT and hardness limitation shall provide the targeted values

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


White Paper: Industrial Control Basics: Contactors
A contactor is an electrical device used for switching an electrical circuit on or off. Considered to be a special type of relay, contactors are used in applications with higher current carrying capacity, while relays are used for lower current applications. Download Now
Research Report: State of IoT Adoption in Product Development 2019
This research report, based on a survey of 234 product development professionals, examines the current state of Internet of Things (IoT) adoption by product design teams, its perceived importance, and what features and capabilities teams consider important when making decision about adding IoT functionality to their products. Download Now
Research Report: Augmented Reality for Maintenance, Repair and Overhaul (MRO)
The term Industry 4.0 denotes a cluster of technologies that’s poised to fundamentally reshape manufacturing and bring about a new industrial revolution. These include 3D printing (AM), the Industrial Internet of Things (IIoT), artificial intelligence (AI) and mixed reality technologies, more commonly known as virtual reality (VR) and augmented reality (AR). Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close