A778 vs A312 SS for ASME Pressure Piping Application

[Specguy]

I recently discovered an equipment manufacturer specifying ASTM A778 tube product for an ASME B31.1 piping application of 150 psig @ 290 deg F. Has anyone else run across the use of this material spec, which is not listed in ASME B31.1 or B31.3, for Power Piping applications? I am aware of it's use in the Pulp & Paper Industry for low pressure non-code applications. A312 or A358 would be my materials of choice.

 

[metengr]

What is the fluid for this application? I personally have not seen this material used in Power Piping, but I am familiar with the specification. By the way, I agree with your final statement.

 

[Specguy]

The fluid is Black Liquor. Sodium Hydroxide (caustic) + lignin (a constituent of wood) at 35-70%. Used as a biofuel.

 

[MJCronin]

Specguy....

It all depends on your application....what is your required pipe size, pressure and liquid SG

For small bore, thin walled piping applications, A778 is probably a better choice than A312 in many applications. Fabrication is supposedly better.

But large bore, higher pressure applications....A312/358 may be a better choice.

MJC