Tube to Tube sheet welding

[Merzi]

I have to Qualify a mock up procedure of Tube to tube sheet weld as per QW 193.

Material is as follows.
Tube Sheet - SA 350 LF2 Class 1
Tubes -SA 334 Gr 3.

Can someone provide me with information regarding the filler wire to be used for welding

 

[metengr]

Considering this appears to be for lower temperature service based on materials of construction, I would recommend using the GTAW process or SMAW process with Ni-containing low alloy filler metal, like

SFA 5.28 ER80S- NI2 GTAW process
SFA 5.5 E7018-CIL SMAW process

if your MDMT is below -30 deg F.

If not, ER70S-6 would work for GTAW.

 

[Merzi]

Metengr.

I apologize for not giving full details. MDMT for this exchanger is -50°F.