ASME BPVC 2023 Code Cases Boilers and Pressure Vessels

Condition: New product

Approval Date: June 23, 2005
Code Cases will remain available for use until annulled by the applicable Standards Committee.
Case 1325-18
Nickel-Iron-Chromium Alloys 800 and 800H UNS
N08800 and N08810 and Nickel-Iron-Chromium-
Molybdenum-Copper Low-Carbon Alloy UNS N08028
Section I
Inquiry: May Nickel-Iron-Chromium Alloys 800 and
800H UNS N08800 and N08810 and nickel-ironchromium-
molybdenum-copper low-carbon alloy UNS
N08028 conforming to the specifications listed in Table
1 be used for water wetted service in Section I
construction?
Reply: It is the opinion of the Committee that nickeliron-
chromium and nickel-iron-chromium-molybdenumcopper
low-carbon alloy forms as shown in Table 1 may
be used for water wetted service in Section I construction
provided the following requirements are met.
a The maximum allowable design stress shall not exceed
that shown in Table 1B of Section II, Part D.
b Welded fabrication shall conform to the applicable
requirements of Section I.
1 The procedure and performance qualifications
shall be conducted as prescribed in Section IX, except that
the tensile strength of the reduced section specimen shall
not be less than the minimum tensile strength of the materials
specified in the Inquiry.
2 Welding on N08800 and N08810 shall be done by
any welding process or combination of processes capable
of meeting the requirements. Welding on N08028 shall be
by the gas tungsten arc process only.
3 Welds that are exposed to corrosive action of the
contents of the vessel should have a resistance to corrosion
equal to that of the base metal. The use of filler metal
that will deposit weld metal with practically the same
composition as the material joined is recommended.
When the manufacturer is of the opinion that a physically
better joint can be made by departure from these limits,
filler metal of a different composition may be used provided
the strength of the weld metal at the operating temperature
is not appreciably less than that of the high-alloy
material to be welded, and user is satisfied that its resistance
to corrosion is satisfactory for the intended service.
4 Where welding repair of a defect is required, it
shall be followed by reexamination as required in
PW-11. Where a defect is removed and welding repair
is not necessary, care shall be taken to contour the surface
so as to eliminate any sharp notches or corners. The contoured
surface shall then be reinspected by the same
means originally used for locating the defect to be sure

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it has been completely removed.
5 When these materials are cold formed, the rules
of Section I, para. PG-19 shall apply for alloys N08800
and N08810. Other than these requirements, any other
heat treatment after forming or fabrication is neither required
nor prohibited, but if heat treatment is applied to
alloy N08028, it shall be performed at 1975°F2085°F
1080°C1140°C followed by rapid cooling.
c This Case number shall be shown on the Data
Report.
CAUTION: Austenitic alloys are subject to stress corrosion
cracking, intergranular attack, pitting and crevice corrosion
when used in boiler applications in aqueous environments. Factors
that affect the susceptibility of these materials are applied
or residual stress, water chemistry and deposition of solids, and
material condition. Susceptibility to attack is enhanced when
the material is used in a sensitized condition, or with residual
cold work. Concentration of corrosive agents e.g. chlorides,
caustic, or reduced sulfur species can occur under deposits
formed on the surface of these materials, and can result in severe
underdeposit wastage or cracking. For successful operation
in water environments, careful attention must be paid to
continuous control of water chemistry.
Table 1
Product Specifications
Form Specification
UNS N08800 and N08810
Seamless condenser and heat exchanger tubes SB-163
Rod and bars SB-408
Seamless pipe and tube SB-407
Plate, sheet, and strip SB-409
Welded tubes SB-515
UNS N08028
Seamless tubes SB-668
Plate, sheet, and strip SB-709
CASE
1325-18
The Committees function is to establish rules of safety, relating only to pressure integrity, governing the construction of boilers, pressure vessels, transport
tanks and nuclear components, and inservice inspection for pressure integrity of nuclear components and transport tanks, and to interpret these rules when
questions arise regarding their intent. This Code does not address other safety issues relating to the construction of boilers, pressure vessels, transport tanks
and nuclear components, and the inservice inspection of nuclear components and transport tanks. The user of the Code should refer to other pertinent codes,
standards, laws, regulations or other relevant documents.
1 1325-18
ASME BPVC.CC.BPV-2023