Weld overlay dimensional tolerance
Weld overlay dimensional tolerance
(OP)
Hello Members
We have a 3in forged nozzle ASTM A 105 Clad with 3 mm SS316L attached to the shell of clad vessel HP separator.
The clad thickness specified is 3 mm.As per approved drawing the bore of base metal of forged nozzle is 73.66 mm and inside dia after cladding is 67.66 mm (73.66-6mm).
My questions are
1)What is the tolerance on the bore dimension 67.66 mm after cladding.
ASME B 16.5 specifies Flange Bore ( without cladding)Tolerance AS +1MM AND -0.0 MM.There is no under size tolerance .The clad thickness is usually more than 3 mm and the surface in our case will be as clad and not machined.An excessive clad thickness will result in reduction of bore size and there can be process issues due to restricted flow turbulence etc
2) What is the surface finish requirement for as clad surfaces?
The design considers 3mm overlay only for corrosion protection and not for strength calculations.
Thanks in advance
Sree60
We have a 3in forged nozzle ASTM A 105 Clad with 3 mm SS316L attached to the shell of clad vessel HP separator.
The clad thickness specified is 3 mm.As per approved drawing the bore of base metal of forged nozzle is 73.66 mm and inside dia after cladding is 67.66 mm (73.66-6mm).
My questions are
1)What is the tolerance on the bore dimension 67.66 mm after cladding.
ASME B 16.5 specifies Flange Bore ( without cladding)Tolerance AS +1MM AND -0.0 MM.There is no under size tolerance .The clad thickness is usually more than 3 mm and the surface in our case will be as clad and not machined.An excessive clad thickness will result in reduction of bore size and there can be process issues due to restricted flow turbulence etc
2) What is the surface finish requirement for as clad surfaces?
The design considers 3mm overlay only for corrosion protection and not for strength calculations.
Thanks in advance
Sree60





RE: Weld overlay dimensional tolerance
RE: Weld overlay dimensional tolerance
RE: Weld overlay dimensional tolerance
you have to add on the "butter" pass thickness.
if we have a 3mm requirement, the weld overlay would wind up 3/15" to 1/4" thick
RE: Weld overlay dimensional tolerance
Thanks for the inputs
sree60
RE: Weld overlay dimensional tolerance
RE: Weld overlay dimensional tolerance
solution 1: you shall check the nozzle neck calculation with thickness 3mm less than drawing, if the new thickness is approved you can revise the drawing and do the overlay after machining else you shall ask your client to accept 3mm of the overlay thichkess as buttering in your calculation because actually you will do 6mm buttering and half of it can be consider in calculation instead of base metal (forge)
solution 2: process designer shall check ID 67.66 mm for flow rate of this nozzle and give you the approval.
if the overlay will accept visually (after PMI test) normally no machining is necessory but you must get the client approval.