Thank you, apetri, got it. Back to the basics.
Yes, that gives the same results for momentum portion of the reaction force (10,000 lbs), in API Part 2 two-phase equation.
I conclude, then, the reason that the two-phase force is so much higher than the force for the vapor alone is that the bulk...
Are you saying API 520, Part II, Equation (2), is derived from the correlation you presented?
Is the correlation from API, ASME or related standard, or from basic fluids?
I'm not clear on the correlation presented. It looks like:
(force) / (speed of sound, squared) = K * (mass flow rate of...
I understand that the IECC is intended to limit energy use in facilities, in balance with first costs.
So, I was surprised that an architectural colleague thought that the IECC (commercial provisions, 2009) would not apply to an interior space to which we are considering adding air...
The 2-phase equation in Part II of API 520 latest edition does not seem to provide results consistent with the API 520 gas/vapor or ASME B31.1 App. 2 steam equation, when the vapor fraction goes to 1.0. I get results about 5 orders of magnitude higher with the API 2-phase equation (seems out of...
Stookeyfpe -
Yes, IBC Table 1604.5 would apply, not ASCE Table 1.1. However, the occupancy category would be the same.
One is Category III, with a process steam distribution main in a refinery, but it also has snuff steam for fire protection.
Another project is Category IV, with a steam...
Stookeyfpe-
Okay, I think a mistake I made is that the material content of a single piping system alone, would define the Occupancy Category.
The Occupancy Category is III: ...other structures...(...that process)...containing sufficient quantities of toxic...substances to be dangerous to the...
Stookeyfpe -
Thank you. Do you know whether the 2009 IFC clarification is to steam without reference to superheat temperature, pressure, or room size?
I see a difference, due to the temperature of the fluid, and the potential rate of heat addition to a space, that makes steam stand apart from...
Would the 2006 Edition of IBC/IFC consider steam to be a hazardous material?
This in effort to determine whether the seismic provisions apply for restraint of steam piping. So, ASCE 7-2005 also factors in, and whether steam is considered hazardous, determins the Occupancy Category in ASCE 7...
This application is high stress, low cycle fatigue (under 10,000 cycles). The tubing is installed, and although new fittings could be coated or electropolished in future installations, if fatigue cracks do develop, there is no benefit with respect to the development of fatigue cracks, to...
Metengr and CoryPad,
Thank you for confirming some of my understanding.
Rather than predicting when a fatigue crack will occur, I'd like to estimate the size of the initial crack, once a crack does begin to occur.
The subject piping surface has a 25 Ra surface finish (~0.64 micron). I'd like...
Is it possible to estimate whether the initial fatigue crack size exceeds 1 micron in Type 316L (A270) without a background in fracture mechanics or metallurgy?
In other words, is the science of crack initiation accessible enough that someone with a mechanical engineering background, not...
Davefitz -
I'm not dealing in the creep range in this instance...yet. Found your discussion on time to temperature helpful in understanding approaches to take in calculating mid-wall temps.
John -
Thank you for the reminder...I hadn't been to Becht's site since January and found it helpful -...
Process Industry Practices (PIP) publishes PNC00004 - Piping Flexibility Analysis Criteria for ASME B31.3 Metallic Piping, which outlines minimum basic requrements for analyzing aboveground metallic piping systems for flexibility. It was last published in 2000.
Anyone familiar with this...
Edward -
Thanks for your thoughts.
Since my initial posting I decided to use the upper temperature limit of the steam delivery contract for the flexibility design. This decision was based on my interpretation that the duration of the temperature event is not a consideration for flexibility...
Our local inspection firm said tops on magnetic partical is 150-200 Deg. F.
Have you used MP at higher temps and can you refer me to a testing firm that you used?
DSB123,
Thank you, yes that does clarify. What I did not understand was that the dead weight supports were removed too and the piping was made weightless. I thought just the supports that were not in place for deadweight were removed.
The fact that it was a proceedure of a past era also...
I want to have a nondestructive evaluation for surface cracks performed in carbon steel fittings at a service temperature of 650 - 700 Deg. F. I understand that use of liquid penetrant or magnetic particle methods would require a shutdown.
A local inspection firm is investigating use of high...
