Stainless Steel fitting specifications

Welding Fittings“As-Welded” Grade

“as-welded” fittings are weldedusing ASME qualified welding proceduresand can be supplied in a wide range ofdiameters and wall thicknesses from any ofthe weldable corrosion resistant alloys.Welding elbows can be provided withsmooth flow or mitered construction, teesand crosses can be drawn outlet or nozzle-welded types and reducers can be conical orbell-shaped Alaskan manufacturers “as-welded” fittings to ANSI B16.9, ANSI B16.28or MSS SP-43 dimensions, with weld endsfurnished square cut. Fittings with special

dimensions orthose that require beveled. belied or roll-grooved ends can be provided. Spotradiography or 100% radiography of weldedseams can also be performed. Alaskanpickles and passivates its fittings to maintaincorrosion resistance and to prevent surfacediscoloration from free iron oxidation. “As-welded” fittings are commonly used with “as-welded” pipe and tubing in pulp and papermills, food processing plants and otherindustries where corrosion resistance isessential.

ASTMA 774This specification covers “as-welded” stainless steel pipe fittings for lowpressure piping intended for low tomoderate temperatures and generalcorrosive service where heat treatment isnot required for corrosion resistance.Fittings are normally furnished per MSSSP-43 dimensions unless otherwise agreedupon between the purchaser andmanufacturer.A 774 is generally considered to be themost applicable ASTM specification for “as-welded” fittings.

Stainless Steel fitting specifications

Welding Fittings (Continued)ASTM A 403This specification includes seamless andwelded wrought austenitic stainless steel buttwelding fittings and consists of two generalClasses. WP and CR. Class WP fittings aremanufactured to the dimensional requirementsof ANSI B16.9 or ANSI B16.28 and havepressure ratings equal to that prescribed forthe specific matching pipe. Class CR fittingsare manufactured to the dimensionalrequirements end pressure ratings of MSS SP-43. Both Classes require carbide solution heattreatment which includes rapid cooling toprevent reprecipitation of carbides, Fitting sub-classes covered by ASTM A 403 include thefollowing specific requirements:

Sub-class RequirementWP.S Seamless constructionWP-W Welded fittings where fitting

construction welds are 100%radiographed or ultrasonicallyexamined and where side med.with the addition of filter metalin any starting material (e.g.,welded pipe) are 100%radiographed

WF-WX Welded fittings where all weldsare 100% radiographedor ultrasonically examined.

CR Seamless or welded fittingswith no nondestructive testingrequired.

Special fittings with sizes and shapes notincluded in the above dimensionalspecifications can be ordered per A 403,provided they are marked “S9” and meet allother requirements of the sub-class specified.

ASME SA-403This specification includes seamless- and welded wrought austenitic stainlesssteel butt welding fittings intended for use ascommercial components that comply withSections I, IV and VIII and nuclear power plant

components that comply with Section III ofthe ASME Boiler and Pressure Vessel Code.With the exception of changes in tensileproperties of 304L 316L and 316N, and theadditional requirements for ASME Codedocumentation,this specification is identical toASTM A 403. Alaskan produces and stocksSA-403 quality fittings, welded with fillermetal and stamped with the “U” symbol (Section VIII) under a Certificate ofAuthorization from the American Society ofMechanical Engineers.

ASTM B 361This specification includes seamlessand welded aluminum and aluminum alloy butt welding fittingsmanufactured to the dimensionalrequirements of ANSI B16.9 and B16.28 andare generally available. in diameters and schedule wallthicknesses shown In ANSI B36,10 and ANSIB36.19 (See page 40).

ASTM B 363This specification covers seamless andwelded unalloyed titanium butt weldingfittings intended for general corrosionresisting and elevated temperature service.Dimensions are in accordance with ANSIB18.9 or MSS SP-43 standards and aregenerally available in diameters and schedulewell thicknesses shown in ANSI B36.10 andANSI 636.19 (See page 40). Alaskanmanufactures these fittings using ASMEqualified welders and welding procedures.

ASTM B 366This specification includes seamless andwelded wrought nickel and nickel alloy buttwelding fittings and consists of two generalClasses, WP and CR. Class WP fittings aremanufactured to the dimensionalrequirements of ANSI B16.9 or ANSI B16.28

and have pressure ratings equal to thatprescribed for the specified matching pipe.Class CR fit tings are manufactured to thedimensional requirements and havepressure ratings of MSS SP-43.Heat treating is optional as agreed uponwith the purchaser. Fitting sub-classescovered by ASIM B 366 include thefollowing specific requirements:

Sub-class Requirement .

WP-S Seamless constructionWP-W Welded fittings where fitting

construction welds are 100%radiographed or ultrasonicallyexamined end where weldsmade with the addition of fillermetal in any starting material(e.g.. welded pipe) are 100%radiographically examined.

WP-WX Welded fittings where allwelds are 100% radiographi-cally or ultrasonically examined

CR Seamless or welded fittingswith no nondestructive testingrequired.