Can I weld A333Gr6 LTCS pipe to A106 Pipe ??

[ak1965]

Due to non availability of A106 pipe material, we need to weld an existing A106 pipe to an available A333 Gr6 LTCS pipe for a Reactor outlet piping modification.

Can I weld A106 Pipe to A333 Gr6 pipe?

If yes, Shoule be the use of E/ER7018 or E/ER8018 welding wires ok for this application? Any other precautions to be taken fr this welding?

 

[metengr]

Yes, you can weld the A 106 to A333 Gr 6. I would recommend using ER70S-2/E7018 H4 weld rod. What is the code of construction? When you find out, I would suggest you review it for preheat and post weld heat treatment requirements, and NDT requirements.

 

[ak1965]

thanks metengr....!

We shall refer....B31.3...!

 

[jmiles]

If im not mistaken they are absically the same pipe, but the A333 has had the notch hardness testing and the A106 has not, is that correct?

 

[ak1965]

yes.....jmiles

i also feel so....the difference is impact tesing & minor chnages in chemical composition..

 

[metengr]

Let’s not get carried away here. A 333 material is for low temperature service, this means material is made using a fine grain practice along with alloy addition and specific heat treatment requirements that promote increased notch toughness. For Grade 6 material, this is close to A 106 Grade B only.

 

[vesselguy]

metengr,
good point about difference between 106A and B grade. Correct me if I'm wrong but it is correct to use the low hydrogen E7018 as you recommended but just have to use an impact tested WPS as the concurrent requirement.

 

[metengr]

vesselguy;
I always specify low hydrogen electrodes when it comes to welding code applications or otherwise. Regarding your statement about an impact qualified WPS, I can't really provide an answer to your question because you may not need an impact qualified WPS for this modification, the OP is using A 333 Grade 6 material as a substitute for originally installed A 106 Grade ?.

 

[ak1965]

Thanks Metengr & vesselguy will let you kno the development.