Furnace Tubes designed to what? 3

[HRS713]

Hello everyone,

We will be smart pigging the convection section of a box furnace and we need to take a tube sample (weld to weld). My question is if the tubes within a furnace are considered pipe and designed to B31.3 or designed to the code of the furnace? Additional question, what are box furnaces designed to?

Thank you very much for your time in advance.

 

[NBrink]

I've seen both 31.3 and Section VIII, although 31.3 is definitely more common. Purchaser's choice in most jurisdictions as far as I'm aware.

Take a look at API 530 and 560 though, lots of good stuff.

 

[NovaStark]

API 530 is usually used to determine thickness. In terms of inspection criteria, typically B31.3 or ASME Sec. 8. Depends on the purchaser as NBrink said.

 

[LittleInch]

According to the scope section of B 31.3 it shouldn't be under B 31.3 (excludes tubes in either fired heater or heat exchangers, so probably should be ASME VIII if the "furnace" is actually electrically heated.

If it's flame heated then should be API 560 or similar.

"box" furnaces or I would call it a kiln - furnace implies flames to me - might just fall outside this designation because of their size or just "industry practice"

If you're "smart pigging" it how big are the tubes and the furnace? Can you get a pig round all the bends?



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[HRS713]

Thank you all for your responses. I will pull up B31.3, API 530 and API 560 as you all have mentioned to review and reference.

LittleInch - Yes, you are correct in that it is a fired heater. The tubes are 6" in diameter and include 180 deg SR U bends, but the smart pigging vendors we've reached out to can get around as low as 1D bends (which is the case in this heater).

Again, I appreciate all of your responses. First time posting on here after utilizing the forums nearly everyday as I begin my engineering career (5 months fresh out of college).

 

[DSB123]

Have a look at ASME I.

 

[weldstan]

Most fired heaters that I have seen (hundreds) have had tube designs either to API 560 or B31.3 In the last 20 years, most have been to API.

 

[DSB123]

weldstan,
As LI says internal heater piping is outside the scope of ASME B31.3

 

[NBrink]

Sure, the wall thickness is per API 530, but there's not much to 530 beyond creep rupture life...

API 560 even says: "The pressure design code shall be specified or agreed by the purchaser. Pressure components shall comply with the pressure design code and the supplemental requirements in this standard."

Weld examination, etc. refers back to the "pressure design code", and let me assure you there are a lot of heaters listing B31.3 on their datasheet as the pressure design code...