PWHT Exemptions D2 to A1

Home Forums General Standards and codes PWHT Exemptions D2 to A1

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #1580
    cassgazz
    Spectator

    I have come across this exemption before. Power station boiler tubes & piping – can’t remember exact thicknesses, but around 60mm OD x 5 – 6mm thick; Material 2.25%Cr, 1Mo.

    P22 material has a maximum allowable carbon content of 0.15% IIRC.

    A1 – Item C refers to parent metal composition. PWHT for carbon steel is not required below thicknesses of 32mm.

    A2 – Yes, correct. Go off the thickness of the thinner material.

    #1582
    Chris
    Spectator

    My point is the combination of the two dissimiar materials one of A106 Gr.B having 0.25% C forms the basis of the joint, there for does that joint still conform to the requriments of the exemption, i dont beleive so.

    a) equal to or less than 12mm

    b) equal to or less than 127 OD

    c) less than 0.15 C content

    Its all a matter of interpretation but im definitly in favour of majority rules, so lets hear some more opinions.

    I might be setting myself up for dissapointment but here goes.

    #1595
    cassgazz
    Spectator

    Chris,

    If the carbon steel is less than 12mm, it automatically does not require heat treatment.
    Carbon steel only requires heat treatment at 32mm and above.

    #1641
    mkseogirl
    Spectator

    cassgazz, I totally agree with you …

Viewing 4 posts - 1 through 4 (of 4 total)
  • You must be logged in to reply to this topic.