How to caculate the operation pressure of boiler . 1

[jamilnama]

Hello Members

How to calculate the operation pressure of boiler if the thickness of the supper heater tubes reduce.
Thank you very much for reply.

best regard
jamil

 

[jamilnama]

The material of supperheater is sus 321 and the design pressure is 157 kg/cm^2 and design temperture 570C .
The design thickness is 4.2mm...
The new thickness is 3mm.
The operation pressure is 134kg/cm^2..

How to caculate the new operation pressure...

thankx

 

[MrBTU]

Jamilnana,
I don't think anyone is going to touch this one - there are so many factors to consider besides the reduced thickness of the superheater tubes.... and we need to understand what you are trying to do, put an old boiler back into service? What's on the nameplate? What about the other components? If you're looking to re-design the boiler, then you need to do that in it's entirety, not just focus on the superheater tubes.

 

[davefitz]

you may need to obtain a recommendation or approval from your "authorized inspector" , who is the independent 3rd party inspector who may be associated with the insurance company that insures the site.

One guideline sometimes used is --If the tubes are completely "within the setting" of the boiler and the wall thickness has eroded or corroded only a small section of the tube's circumference ( perhaps 60 degrees out of 360 degrees) then no derate may be needed if the remaining wall thickness is at least 50% of the minimum required per code calculation.

The code calculation used to determine the minimum required wall thickness is defined in whatever desing code was used to design the boiler.