subrata169,
An ASME B31.3 golden weld is a non-hydrotested weld , which instead is examined per 345.9.1. That section specifies RT or UT, not necessarily RT.
If your client insists on RT, then you should tell him that RT is not adequate for this geometry, as pdprau and others have pointed...
Subrata169,
So you missed out a 2" connection and you now wish to add it to the already hydro tested header - but you don't want to repeat the hydro test because it is just too much work?
I don't think it is good practice to skip the hydro test for no better reason than that. But you may get...
Chucks,
I suggest that you use more descriptive titles for your threads than 'Hi All'. That way other forum users will not have to open the post to see what is all about and might also increase your chances of useful replies.
Leopard,
I doubt that you can get a standard thermowell to fit into a 1" line. Our company standard only has thermo wells for 4" lines and larger. A common way of fitting thermowells into small bore lines is locally to increase the pipe bore to 4". A detail for that can be found in Norsok...
Lummy02,
You aware of the possible galvanic corrosion issues by combining stainless steel/brass with carbon steel, right? Depending on a number of factors, it might not be a problem in your application, but would be interesting to hear how you have come to the conclusion that it is not a concern.
Not that I necessarily agree on supporting piping on rod bars. But the idea behind it is to reduce the area between the pipe and the support where moisture can get trapped and lead to crevice corrosion. That idea has some merit. In many environments, loss of integrity due to corrosion is a more...
pipe15,
You can't expect a ASME B16.9 fitting to have the specified wall thickness at all points, only at the connecting ends. That some parts of the fitting will have a heavier wall thickness is pretty much a given. The manufacturer should probably strive to maintain the ID and have the extra...
I am used to the stress analysis being documented by a stress report issued to the client. In addition to the stress isometrics serving internal communication purposes during the design, they are an essential part of the stress report - without them it would be nearly impossible to read the...
nipra03,
My thoughts are (based on B31.3 only, the other B31’s are probably similar):
ELBOWS
Normally ASME B16.9 standard elbows are used. These are B31.3 'listed components', i.e. approved by the code for use in piping systems, ref. table 326.1. If you modify these in any way, they become...
Hmmmm, for at calculation to demonstrate rupture for a one-of applied load, the calculated stress would have to be well above the ultimate tensile strength for the material, even with the SIF's set to 1. So if that is what you have, I say congratulations, you have solved the mystery.
I write...
Lewist57,
In answer to you questions:
1a) '...does not the pipe drop event cause a sudden load that could overstress the elbow at the end of the line and cause it to fracture?' Yes. It is not very likely but cannot be ruled out with the information we have.
1b) '...I am just trying to...
Curtis2004,
Your points are all valid. But should we not concentrate on answering the question that is asked in this thread? Until proven otherwise, we must assume that the person asking knows what he is after.
Lewist57 is in this instance asking himself whether the sudden stress from a...
Lewist57,
I understand your question to be whether you can use Caesar II to calculate what the stress the failed elbow would have seen when the support failed. The answer is YES, and I have already outlined to you two alternative ways for you to do it.
It is not clear to me what more you are...
Lewist57,
I am sure there are ways to do it dynamically in Caesar II, e.g. by using time history analysis and modelling the support as a force equal to the support force in the corresponding static load case and then suddenly letting the force drop to zero.
A simpler way would be do two static...
As Fegenbush points out, on thick sections there could be an economic advantage of J-welds, as they require less welding.
Additionally, J-welds can be better quality, as the less welding means less heat input and hence the heat affected zone (HAZ) will tend to be smaller. In other words: Less...
Thanks for the additional info, Lewist
I think we need to get the terminology right:
Work hardening is an increase in yield strength caused by plastic deformation. Loads that results in a stress higher than the original yield strength will work harden the material. Since the yield is...
Hmmmmm, interesting case, but I think we will need a bit more information.
- What makes you think that this is low cycle fatigue? How did you rule out other possible causes, e.g. high cycle fatigue or sub-standard (brittle) material?
- What kind of cyclic load do you have in mind? You...
Shaff,
In my view GRE firewater systems should undergo surge analysis. One consideration is that this is a safety critical system. Another is that, as LittleInch mentions, GRE is not ideal for water hammer and other dynamic loads. On some newly installed platforms operated by a company where I...
Hmmm, you don't mention why it is required to know the tube growth to install the TI's. Without that being known, it is difficult to understand what is required in terms of calculation and calculation accuracy.
Unless you have existing calculations for the same or similar furnaces - or an...
