Reduction of Scale during PWHT?
Reduction of Scale during PWHT?
(OP)
I am currently involved in the design of a jacketed pressure vessel. Per the ASME code, we are required to complete a PWHT. The vessel is very simple and there is nothing out-of-the ordinary with the design. However, we are concerned that a PWHT would create scale/oxidation inside the jacket that is is not accessible for cleaning/gritblasting.
Are we over-reacting? are there easy (cheap) ways to prevent oxidation/scale?
Oh yeah, the tempeprature is 1100F for 4 hrs or so...
Are we over-reacting? are there easy (cheap) ways to prevent oxidation/scale?
Oh yeah, the tempeprature is 1100F for 4 hrs or so...
John Andrews, PE
Mechanical Engineer
Artisan Industries Inc.
www.artisanind.com





RE: Reduction of Scale during PWHT?
It will not scale at the temperature you state. You will get a little heat tint which is not detrimental to the heat transfer process.
RE: Reduction of Scale during PWHT?
At 1100 deg F, you will have slight oxidation on the surface with no real scale build-up.
RE: Reduction of Scale during PWHT?
John Andrews, PE
Mechanical Engineer
Artisan Industries Inc.
www.artisanind.com
RE: Reduction of Scale during PWHT?
I'am a loss to the reason for the concern over the heat tint. On a lot of our equipment we purposely create a heat tint (bluing) on carbon steel jacketed equipment.
Could you post what will be inside the jacket.