Preheat in asme 9 1

[duongwe]

hi all, i am caring to make a WPS in ASME IX, when i propose a pWPS with Preheat but i see obstacle so i don't know how to choose temperate range suitable to material.Can i see where in ASME IX?

 

[metengr]

ASME B&PV Code, Section IX does not provide preheat recommendations (temperatures), these can be found in the specific book sections of ASME Section I, IV, VIII, etc.

 

[DVWE]

See ASME Section VIII, Non-mandatory Appendix R for preheat recommendations. About the best guide for interpass temperature that I have seen in API 582 (welding guidelines for the oil and gas industry).

 

[duongwe]

thanks all, i forget there is ASME B31.3 in use. can i see where preheat recommendations in B31.1?

 

[metengr]

Yes. For B31.1 see
131.4 Preheat Temperature
The minimum preheat for all materials shall be 50°F
(10°C) unless stated otherwise in the following paragraphs.
131.4.1 Thickness referred to is the greater of the
nominal thicknesses at the weld of the parts to be joined.
131.4.2 P-No. 1. 175°F (80°C) for material that has
both a specified maximum carbon content in excess of
0.30% and a thickness at the joint in excess of 1 in.
(25.0 mm). Preheat may be based on the actual carbon
content as determined from a ladle or product analysis
in accordance with the material specification in lieu of
the maximum carbon content specified in the material
specification.
131.4.3 P-No. 3. 175°F (80°C) for material or product
form that has either a specified minimum tensile
strength in excess of 60,000 psi (413.7 MPa) or a thickness
at the joint in excess of 1?2 in. (13.0 mm).
131.4.4 P-No. 4. 250°F (120°C) for all materials.
131.4.5 P-Nos. 5A and 5B
(A) 400°F (200°C) for material which has either a specified
minimum tensile strength in excess of 60,000 psi
(413.7 MPa), or has both a specified minimum chromium
content above 6.0% and a thickness at the joint in excess
of 1?2 in. (13.0 mm)
(B) 300°F (150°C) for all other materials having this
P-Number
131.4.6 P-No. 6. 400°F (200°C) for all materials.
131.4.7 P-Nos. 9A and 9B
(A) 250°F (120°C) for P-No. 9A materials
(B) 300°F (150°C) for P-No. 9B materials
131.4.8 P-No. 10I. 300°F (150°C) with an interpass
temperature of 450°F (230°C) maximum.

 

[duongwe]

can i see where preheat recommendations in B31.3?

 

[DVWE]

They are probably exactly the same...