differient requirement for nozzle weld PWHT, ASME I no require heating band shall extend the completey around the header, but ASME 31.1 require heating band shall extend completely around the header.
We fabrication the boiler external pipe. Can we PHWT the attachment welds like the method in the following photo?
ASME I PW-39.5.2 "Local areas around nozzles or welded attachments in the larger radius section of double curvature headers. or spherical shells or heads, may be post weld heat treated by heating a circular region around the nozzle. This region, or soak band, shall include the nozzle or welded attachment and shall be measured from the center of the nozzle or attachment. The soak band shall be a circle whose radius is equal to the radius at the widest width of the width of the weld attaching the nozzle or attach ment to the shell, plus the thickness of the shell or head, or 2 in.(50mm), whicherver is less. The portion of the vessel outside of the circular region shall be thermally shielded using blankets, brick, or other suitable insulation material so that the temperature gradient is not harmful. A greater amount of base material may also be heated to permi temperature gradient control."
ASME 31.1 132.7 "For nozzle and attach welds, the width of the band heated to the PWHT temperature shall extend beyongd the nozzle weld or attachment weld on each side at least two times the header thickness and shall extend completely around the header."
ASME I refers to power boilers, whereas ASME B31.1 refers to power piping, i.e. the piping that belongs to a boiler house or a thermal power plant.
So, in my opinion (but I may be wrong), ASME I is talking about nozzels that make part of a boiler, either the boiler itself or its auxiliary headers. On the other hand, B31.1 is talking about nozzles welded to headers that make part of a piping system.
If I'm wrong, someone please correct me.
Giovanni S. Crisi
Sao Paulo - Brazil
the pipe we fabircating belongs to Boiler External Piping of supercritical boiler, as per ASME I 2010 PG-58.3.3 AND ASME B31.1 2007 Fig.100.1.2(A), for boiler external piping the ASME BPVC has toal administrative jurisdiction(mandatory certification by code symbol stamping, ASME Data Forms, and Authorized Inspection).
Today I read ASME I PG-58.3 "The materials, design, fabrication, installation, and testing shall be in according with ASME B31.1, Power Piping."
If it is Boiler External you fabricate to B31.1. Take a look at the notes in the jurisdictional diagrams.
The Section I application has to do with administrative which essentially means Data Reports and an AI.
dragon, you meant to type: "in
accordance with ASME B31.1, Power Piping." As opposed to what you posted.
Respectfully,
Henry
