Material selection ASTM A192 for Super Heater.

[Figueredo]

Hi to All

I have a question about selection carbon steel for super heater bagasse boiler i have ASTM A192 2" i can use this material?

temp desing: 470 °C

tem operation 380°C

Desing pressure: 375 Psig

Operation presure: 250 Psig

thanks for your helps.

 

[metengr]

At 380 deg C operating conditions the SA 192 carbon steel tube material is acceptable for the bagasse boiler. The design temperature of 470 deg C, however, is above what I would like to see in service. Why is this so high relative to your operating condition?

 

[Figueredo]

thanks for you reply.

the design temperature gave me the design engineer other conditions it is that the combustion gases are very abrasive due to bagasse ash is not completely burned and in some cases the diesel contains more than 3% of sulfur.

during the inspection I could see a lot of abrasion , looks like a mild sandblasting .

the temperatures of the combustion gases exceed 600 degrees Celsius (heat exchange) an internal condition i explain in my last question.

thanks.

 

[metengr]

Figueredo
What is the current tube material in the SH? The abrasion could possibly be handled by tube shields. The diesel fuel is used for start-up or is it supplementary fuel during operation? Do you have any wastage from corrosion?

 

[mrfailure]

The design temperature exceeds maximum allowable by at least some boiler manufacturers. I would not use A192 for that reason, but instead would go to a chrome-molly grade like T11.

 

[Figueredo]

sa 213 t22 but, now i have sa 192 seamless we need start soon as possible. i know is not a good material for this conditions. is possible operated 5 months??

 

[metengr]

Figueredo;
Ok, now the real reason is apparent based on my question of what is currently installed. If you understand that this material will be limited in service life, you probably could get 6-12 months. This is less than desirable but having worked in Power Generation for over 40 years I understand where you are coming from.

 

[Figueredo]

I dont have any wastage corrosion i see only this mild sandblasting in some areas, is ubicated in the principal area for combustion gas circulation. the condition and coloration tubes surface looks like good but i see only abrasivity conditions.

 

[Figueredo]

i hope work 6 month, we need make some configuration in the operation condition to a level safe.

thanks.