Hello,
I just finished reading thread404-160050 and I learned alot regarding the use of von Mises equivalent stress equation. My simple question revolves around a 4" pipe that is pressurized and has an external load on it. (See the attached sheet for hand calculations. This is just a...
I am curious about repairing 1.25 Cr - 0.5 Mo vessel plate that has been in service in a catalytic reformer at 900F for 25 years. The nozzle repads show cracking in the HAZ when exposed to wet MT. I have read various articles regarding repair techniques. Some recommend a PWHT cycle of 1300F...
Thank you all for your valuable comments. I appreciate the documentation on copper valves threaded to CS pipe. I tend to agree with EdStainless; since the boiler feedwater has oxygen scavengers in it as well as corrosion inhibitor, the conductivity would be very low. These bronze valves are...
I have a question that revolves around the galvanic corrosion mechanism. If I use threaded bronze valves in a carbon steel boiler feedwater circuit, will there be a concern with galvanic corrosion in the threaded joint? (Temperature is 400F at 250 psi.)
I was reading an API document regarding inspection for austenitic stainless steel heater tubes. It stated that carburized areas of 300 series tubes will have magnetic properties. Can anyone explain this to me on a metallurgical level?
I was wondering if anyone has found any more study material or study guides for the Metallurgical Engineering PE exam. I am only aware of the one that TMS advertises on thier website. Are there classes or other books offered?
Thank you all for the good responses to my question. Mittal has some great literature for answering my question; however, I would like to find a more detailed answer regarding the mechanism for reduction in tensile strength with increased PWHT time. Am I safe to assume that the normalized...
I am in need of some data for predicting the reduction of tensile strength in 2.5" thick SA516-70 normalized at varying PWHT times. I have read on some threads about the Hollomon-Jaffee Parameter, but I haven't had any experience with this equation. Can someone help me out?
I have a general question regarding the design of bolted connections: If bolts are tightened beyond thier elastic limit for structural applications, what potential harm will this cause? I know the AASHTO code discusses this topic regarding direct tension indicator washers. (If the washers are...
Thanks to all for the valuable information. The ends of the pipe will be covered up so drafting would be minimal. I really just needed the equation for a ballpark estimate since there is an abrasion resistant refractory lining that I'd like to stay away from. The attachment of a T/C is...
I have a relatively simple problem on heat flow, but my knowledge in this department is limited at best. I have the following situation: I need to heat up an 8" sch. 80 304H SS pipe to 1900°F and do some light bending. (We will use a 4" wide low voltage heater band typically designed for...
I was looking in API 530 (Calculation of Heater Tube Thickness in Petroleum Refineries), and they reference some of the ASTM Data Series publications. In particular, they reference ASTM DS5S2 and ASTM DS11S1. Can anyone tell me where I can find this data?
This question applies to bolted structural connections. Can a manual torque wrench apply the same tension to a fastener as an impact wrench qualified on a skidmore? (Assume bolts are to be tensioned to 39,000 psi.) In other words, does a properly operating impact wrench apply more effective...
We are currently erecting structural steel that will hold refinery equipment and piping. The contractor is putting sub-assemblies (beam-to-column connections and cross-bracing) together on the ground and performing a final torque. These 10 ton sub-assemlies are then lifted into place and...
Can anyone tell me why ASME IID limits design temperatures to 900F for 2 1/4Cr - 1Mo - 0.25V steels? (Non vanadium modified steels are good up to 1200F.) If you can give me a detailed metallurgical mechanism, that would be great. Also, I have read that PWHT for extended times (multiple repair...
