USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
(OP)
Good day Gents,
I am building two clad vessels one LP NAG INLET SEPARATOR applicable code ASME Div. VIII(I.D-3200 TTL-6700 thickness-90mm; plate mat'l A537 Cl 1 ) & one COMPRESSION SUCTION SCRUBBER applicable code PD5500 (I.D-1500 TTL-3500 THK-47mm; plate mat'l A516 Gr. 70) with 3mm SS weld overlay which will undergo PWHT, the plates for the shell of the vessels are produced with 3mm SS clad. Our fabrication process involves back grinding the SS overlay away from the edge of the plate so that we can weld with normal carbon steel consumables after which comes rolling and welding the long seam (LS) & the circ. seam (CS).We usually make use of SMAW process in welding the back grinded overlay using E309LMo-17 (2 runs) then E316LMo-17. However, this process is quite slow given the size of the LP NAG which has an ID of 3200mm. Is it acceptable to use FCAW process with appropriate consumable to carry out the welding considering the vessel will be PWHT. If the FCAW proceess can be used what should i watch out for when qualifying the welding procedure. For the ASME code are the tests stated on QW-453 IN ASME IX sufficient when qualifying the procedure, for the PD5500 please advice applicable test to be carried out when qualifying the procedure. Many thanks in anticipation to your responses.
Best regards,
Olubaji
I am building two clad vessels one LP NAG INLET SEPARATOR applicable code ASME Div. VIII(I.D-3200 TTL-6700 thickness-90mm; plate mat'l A537 Cl 1 ) & one COMPRESSION SUCTION SCRUBBER applicable code PD5500 (I.D-1500 TTL-3500 THK-47mm; plate mat'l A516 Gr. 70) with 3mm SS weld overlay which will undergo PWHT, the plates for the shell of the vessels are produced with 3mm SS clad. Our fabrication process involves back grinding the SS overlay away from the edge of the plate so that we can weld with normal carbon steel consumables after which comes rolling and welding the long seam (LS) & the circ. seam (CS).We usually make use of SMAW process in welding the back grinded overlay using E309LMo-17 (2 runs) then E316LMo-17. However, this process is quite slow given the size of the LP NAG which has an ID of 3200mm. Is it acceptable to use FCAW process with appropriate consumable to carry out the welding considering the vessel will be PWHT. If the FCAW proceess can be used what should i watch out for when qualifying the welding procedure. For the ASME code are the tests stated on QW-453 IN ASME IX sufficient when qualifying the procedure, for the PD5500 please advice applicable test to be carried out when qualifying the procedure. Many thanks in anticipation to your responses.
Best regards,
Olubaji





RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
Designers specify it without pondering whether fabricators can actually achieve it. Fabricators can NOT achieve 'stainless'* with any conventional, commercially viable process within that window, although most will unblinkingly proceed to weld. Even the AI doesn't ask questions, but I can show you many back-clad 316L steel shell courses with a nice straight red strip on the inside after having been stored out in the weather (if I still had the photos).
I won't go into the details that any competent WE should understand, but suffice to say it is nigh on impossible to deposit a layer of FCAW less than 3mm thick.
* Exactly what 'stainless' means is not usually defined in the spec or on the fab drawing.
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL
RE: USING FCAW PROCESS FOR SS OVERLAY IN A CLAD VESSEL