7/17/2019 WRC 297 Vs WRC 107

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Whenever Pressure Vessel or Heat exchanger (Static Equipments) nozzle loads exceeds the allowablevalues provided b Vendors (Equipment manu!acturer) or standard pro"ect speci!ic tables (guidelines)# thepiping stress pro!essional is permitted to use W$% &'*+ (or an other ,E-) to chec. the stresses atthe /ozzle0Shell "unction point and chec. the stresses with allowable values provided b %odes1 2! thestresses are !ound to be within allowable limit then the load and moment values can be accepted withoutan hesitation1 However there are some boundar conditions which must be met be!ore using W$%1 3his

small write up will tr to explain the required details !or per!orming W$% &' and W$% *+ using %aesar22 and step b step method !or per!orming W$% chec.14oth W$% &' and W$% *+ deal with 5local6stress states in the vicinit o! an attachment to a vessel or pipe1 -s indicated b their titles# W$%0&' canbe used !or attachments to both spherical and clindrical shells while W$%0*+ onl addresses clinderto clinder connections1 While both bulletins are used !or nozzle connection1 W$%0&' is based on un0penetrated shell# while W$%0*+ assumes a circular opening in vessel1 ,urthermore# W$%0&' de!inesvalues !or solid and hollow attachments o! either round and rectangular shape !or spherical shells butdrops the solidhollow distinction !or attachments to clindrical shells1 W$%0*+# on the other hand# isintended onl !or clindrical nozzles attached to clindrical shells1

Boundary condition for using WRC 107:

3o determine whether W$% &' bulletin can be used !or local stress chec.ing the !ollowing geometrguidelines must be met7&1 d89'1::*1 8m3;(803)3<=' (Here# 3;Vessel 3hic.ness# 8m;mean diameter o! vessel)Boundary condition for using WRC 297:

3o determine whether W$% &' bulletin can be used !or local stress chec.ing the !ollowing geometrguidelines must be met7&1 d89;'1=*1 dt<;*' and dt9;&'' (Here t;nozzle thic.ness):1 83<;*' and 839;*=''

>1d3<;==1 /ozzle must be isolated (it ma not be close to a discontinuit) ? not within *@(83) on vessel and notwithin *@(dt) on nozzleDifference between WRC 107 and 297:

3he ma"or di!!erences other than the boundar conditions mentioned above are listed below7&1 W$% &' calculates onl the vessel stresses while W$% *+ calculates Vessel stresses along withnozzle stresses1*1 W$% *+ is applicable onl !or normall (perpendicular) intersecting two clindrical shells whereasW$% &' is applicable !or clindrical as well as spherical shells o! an intersection1:1 3he attachments !or W$% *+ chec.ing must be hollow but W$% &' analzes clindrical or rectangular attachments which can be rigid or hollow1>1 W$% *+ is not applicable !or nozzles protruding

inside the vessel (,ig &)# 3angential /ozzle (,ig*)# /ozzle at angle (,ig :)1

7/17/2019 WRC 297 Vs WRC 107

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=1 3picall# W$%0&' is used !or local stress calculations and W$%0*+ is used !or !lexibilitcalculations1Limitations of WRC:

Ather than boundar conditions mentioned above there are !ew more limitations as mentioned below7&1 /either bulletin considers shell rein!orcement nor do the address stress due to pressure1*1 %-ES-$ 22 #PVElite B %ode%alc will not extrapolate data !rom the charts when geometric limitationsmentioned above are exceeded1 Extrapolated data ma not be appropriate