NSB Class XXII

{{Expand language|langcode=no}}

{{Infobox locomotive

| name = NSB Class XXII

| powertype = Steam

| image = Setesdalsbanen 9mai2004.JPG

| alt =

| caption = Class XXII in front of a Class XXI

| designer =

| builder = Dübs & Co. (2), Thunes Mekaniske Værksted (1){{sfn|Cranfield|2000|page=75}}

| ordernumber =

| serialnumber = Dübs 3174–3175,
Thune 7

| buildmodel =

| builddate = 1895 (2), 1902 (1){{sfn|Cranfield|2000|page=75}}

| totalproduction = 3

| rebuilder =

| rebuilddate =

| numberrebuilt =

| whytetype = 2-4-2T

| uicclass = 1′B1′ n2t

| gauge = {{track gauge|1067mm|lk=on}}

| leadingdiameter =

| driverdiameter = {{Convert|1143|mm|in|abbr=on}}

| trailingdiameter =

| minimumcurve = {{Convert|100|m|ft|abbr=on}}

| wheelbase =

| length = {{Convert|7900|mm|ft|abbr=on}}

| width =

| height =

| axleload =

| weightondrivers = 12 t

| locoweight = {{Convert|17.4|t|ST LT|1}}

| tenderweight =

| locotenderweight =

| tendertype =

| fueltype = Coal

| fuelcap = {{Convert|800|kg|lb|sigfig=3|abbr=on}}

| watercap = {{Convert|1800|L|impgal usgal|abbr=on}}

| tendercap =

| sandcap =

| boiler =

| boilerpressure = {{Convert|145|psi|kPa|0|order=flip|abbr=on}}

| feedwaterheater =

| firearea = {{Convert|7.5|sqft|m2|order=flip|abbr=on}}

| tubearea =

| fluearea =

| tubesandflues =

| fireboxarea =

| totalsurface = {{Convert|62.7|sqft|m2|order=flip|abbr=on}}

| superheatertype =

| superheaterarea =

| cylindercount = Two, outside

| cylindersize = {{Convert|279|x|457|mm|in|abbr=on}}

| frontcylindersize=

| rearcylindersize =

| hpcylindersize =

| lpcylindersize =

| valvegear =

| valvetype =

| valvetravel =

| valvelap =

| valvelead =

| transmission =

| maxspeed = {{Convert|55|km/h|mph|abbr=on}}

| poweroutput =

| tractiveeffort =

| factorofadhesion =

| trainheating =

| locobrakes = Hand brake; Carpenter brake from 1900

| locobrakeforce =

| trainbrakes =

| safety =

| operator = Norwegian State Railways

| operatorclass =

| powerclass =

| numinclass =

| fleetnumbers = 3, 4, 6

| officialname =

| nicknames =

| axleloadclass =

| locale = Setesdal Line

| deliverydate =

| firstrundate =

| lastrundate =

| retiredate =

| withdrawndate =

| preservedunits =

| restoredate =

| scrapdate =

| currentowner =

| disposition =

| notes = References: {{sfn|Cranfield|2000|page=78}}{{Additional citations needed|date=May 2025}} (unless where noted)

}}

NSB Class XXII is a steam locomotive class designed by the Norwegian State Railways exclusively for use on the Setesdal Line.