Is there a stress difference? As I mentioned there are some different creep constants in the FFS-1 code I find interesting. I would think there would not be a difference as ASME Section II Part D does not show different values for SA213 T22 or T11.
While true, there are different heat treatment methods which may result in the same MINIMUM strength and hardness requirements yet, have different creep coefficients. I guess my real question is which heat treatment does ASME section II part D use for allowable stresses in the creep range when...
Please this questions is cross posted in a couple of threads.
Hi all, I have an interesting query as I have not noticed this before. Hopefully someone here has some background.
OK, as an industrial boiler specialist I was putting together an in house data base which compares ASME allowable...
Yes, I noticed that as well. There are also some interesting differences below the creep range. I wonder if this should be a clarification question for ASME Section II Part D? It seems odd to me this is not addressed for materials operating in the creep range. For older equipment the...
LOOK AT ASME SECTION II PART D, 1-100. Below the creep range there are 4 criteria:
The lowest stress of the following is to be used (Post 1998 Code):
Tensile at room temp / 3.5
2/3 yield at room temp
Tensile at temperature / 3.5
2/3 yield at temperature
Hi all, I have an interesting query as I have not noticed this before. Hopefully someone here has some background.
OK, as an industrial boiler specialist I was putting together an in house data base which compares ASME allowable stress in ASME Section II, table 1a to FFS-1 calculated stresses...
Ok, I know this is a long shot, but here it goes. I have an old howden ID fan on a power boiler (biomass) that has seen its fair share of erosion. The impeller to hub bolts are still in decent condition, however we are looking at having to replace the nuts. I am a fairly seasoned and...
Are you only chemical cleaning the boiler drum? This is not a typical cleaning if you are. Deposits located in the drum do not reflect the amount of deposits in the remainder of the boiler.
Has there been a sample tube taken from the high heat zone (ie. burner zone) and a DWD (deposit weight...
Would anyone have information on an old David Brown NH-12 gear box; by old I mean 1940's vintage. I have a client in the Pulp and Paper industry that is looking to increase the horsepower on their existing gear box (and they do not have the $$ to buy and install a new gear box). I am looking...
Simple solution - use feedwater flow minus you extractions (steam/water) to figure out your steam flow. It is usually more accurate.
Extractions could be - blowdown, sootblower steam, attemperation (only if a sweetwater condensor is not used)
Okay - long winded explaination:
A boiler...
You will want to take a look at NFPA 85 (Boiler Combustion Systems Hazards Code) which lists the current standards (also check with the local jurisdiction).
Specifically in the NFPA take a look in Annex A and the figures that show typical fuel supply systems - then let your fingres do the...
Most boiler OEMs design for an average life of 250,000 hrs for north america- however as mentioned, this is not mentioned in the code. Outside of north america boiler life is usually part of the bid specifications.
Take a look at the Babcock & Wilcox book, "Steam, its generation and use". It pretty much has everything. One word of caution - it might be a little overwhelming.
Cheers.
okay - nothing on 1340 - sorry - if it helps ASTM A 829 is equivalent to 1340.
For steels with over 0.3% carbon I do have some info on the modulus - it drops well below 15x10^6 psi above 1200-F I don't know about its suitablility for use over 1200 F
Sorry - nothing on 4140 - guess I wasn't...
If your in Canada, and I am assuming you are based on the B31.3 reference, you should refer to ASME Section II - it lists approved materials and strengths at temperatures (B31.3 refers to it but I can't remeber off hand what section it's in).
If your designing within a Canadian juristiction...
