Heat input for each pass or for each layer ( ASME IX)?
Heat input for each pass or for each layer ( ASME IX)?
(OP)
When heat input is required is it mandatory to perform the measures for each pass ? or is it sufficient to do the measures for each layer .( according to ASME IX)
thank you
thank you





RE: Heat input for each pass or for each layer ( ASME IX)?
From my perspective, continous monitoring is required when supplemental essential variables apply to insure compliance to Code.
RE: Heat input for each pass or for each layer ( ASME IX)?
Jeff
RE: Heat input for each pass or for each layer ( ASME IX)?
Abdomen,
Each layer may be made up of 1, 2, 3, 4 or more beads and the amps, volts and travel speed should remain constant for all.
If there is a change for some reason in amps, volts or travel speed for an individual bead (within a layer)then that should be recorded, otherwise record per layer.
Of course a layer may consist of a weave or multiple beads which will have a large difference in heat input so this must be clearly shown on the WPS/PQR.
pass: a single progression of a welding or surfacing operation
along a joint, weld deposit, or substrate. The result of
a pass is a weld bead or layer.
layer: a stratum of weld metal consisting of one or more
beads. See figures QW/QB-492.1 and QW/QB-492.2.
Cheers,
Kiwi
RE: Heat input for each pass or for each layer ( ASME IX)?
RE: Heat input for each pass or for each layer ( ASME IX)?
Heat input shall be determined for each pass and each layer. No of passes may or may not be equal to no of layers. PQR is the record what happend during the welding of test coupon, so each pass heat should be determined.
Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN
RE: Heat input for each pass or for each layer ( ASME IX)?
Heat input is a result of amps/ volts / travel speed so if you put 4 beads (eg. a heavy wall pipe) in one layer and no parameters were changed why would you have to measure every bead ?
Regards,
Kiwi
RE: Heat input for each pass or for each layer ( ASME IX)?
Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN
RE: Heat input for each pass or for each layer ( ASME IX)?
My practice is to record all parameters for all beads on a PQR. You can't be sure that heat input is actually 'constant' until you've subsequently done the math. How fussy you want to be about it is up to you and your inspector, and how critical the procedure is.
When I know that a steel has a large margin of safety (in terms of exceeding impact requirements) I will ask for high heat input in the qualification test. Then not only can I sleep better, but monitoring becomes simpler, because in practice welders will always work comfortably within the limits of the WPS parameters.
RE: Heat input for each pass or for each layer ( ASME IX)?
On the other hand, during welding production; stringency of heat input measurement frequency requirement varies among metallurgy type CS/LTCS/SS/SDSS/Titanium/CUNI for the purpose of avoiding expected defects related to the previously mentioned.