Posted by: sggodbole
B31.3/31.1 - New edition - 07/09/02 08:08 AM
Is the new edition of B31.1 and 31.3 codes expected in year 2002 ?
If yes - when ?
If it is already out -then are there any changes from stress analysis point of view ?
Regards,
Sunil
Posted by: Richard Ay
Re: B31.3/31.1 - New edition - 07/09/02 01:18 PM
<font color="0000ff">Are new B31.1 and B31.3 codes expected in 2002?</font>
The most recent edition of B31.1 was issued on Dec 10, 2001. I doubt if an addenda will be published before Dec 2002.
The most recent edition of B31.3 is dated April 30, 2002.
For B31.3, I understand that yearly addenda will no longer take place. Instead, the code will be republished every two years.
<font color="0000ff">Are there any changes from a "stress analysis "point of view?</font>
B31.1
Yes. The new code has changed the expansion coefficients. Additionally, "code case 173" allows alternate allowable stress values.
B31.3
While I have not studied this new edition in depth, the changes do not appear to affect things from a "stress analysis" point of view.
Posted by: roveran
Re: B31.3/31.1 - New edition - 07/19/02 03:34 AM
The ASME B31.1(2001 ed.) has changed the expansion coefficients. But I think the material DB in CII does not revised according to the latest ASME B31.1(2001 ed.).
For example, A106-B Thermal Expansion Data(App.B)
2001 edition, 6.9 x 10e-6 in/100ft at 300F
In CII, the value is 6.6 x 10e-6 in/100ft at 300F
Also, in output file, the edition of ASME B31.1 is printed '1998', not '2001'.
Regards,
Posted by: Richard Ay
Re: B31.3/31.1 - New edition - 07/19/02 08:26 AM
The most recent <em>Edition</em> of B31.1 is the 2001 Edition, published on Dec 10, 2001. Prior to this, the most recent <em>Edition</em> of B31.1 was the 1998 Edition, which included two <em>Addenda</em>. The first was published in 1999, the second in 2000.
The date of the supported codes is reported at the top of the Stress Report. CAESAR II reports: the code name (B31.1), the date of the Edition (1998), and the date of the latest addendum addressed (Sept 15, 2000).
So yes you are correct. CAESAR II Version 4.40 does not yet support the material changes made in the 2001 Edition. We could not implement these changes for the 4.40 release due to the QA involved (considering all the other changes made to the software). Our plan is to make a revised material database available in a <em>build</em> to Version 4.40 as soon as possible. This will involve an additional QA Series on our part, but it is the fastest, safest way to get this change into users hands.
In the meantime, if you must use the new expansion coefficients, you can do so. Just type in the desired coefficient (in units of length/length) in the temperature field. CAESAR II will assume the value is an expansion coefficient if its magnitude is less than the ALPHA_TOLERANCE specified in the configruation file.
Posted by: Edward Klein
Re: B31.3/31.1 - New edition - 08/07/02 08:14 AM
How do the new B31.1 coefficients compare to the latest B31.3? Were they changed to match each other, or are the two codes diverging?
Posted by: Richard Ay
Re: B31.3/31.1 - New edition - 08/07/02 09:16 AM
Prior to the recent B31.1 edition, the expansion coefficients were almost the same between B31.1 and B31.3. The new B31.1 changed these coefficients. The table below shows the values for "low carbon" steels.
<table border="1" cellpadding="10" bordercolor="#0000ff"><tr><th>Temp (°F)</th> <th>New B31.1</th> <th>Old B31.1</th><th>B31.3</th></tr><tr><td>-325</td> <td>5.5</td> <td>5.0</td> <td>5.0</td></tr><tr><td>-150</td> <td>5.9</td> <td>5.5</td> <td>5.5</td></tr><tr><td>-50</td> <td>6.2</td> <td>5.8</td> <td>5.8</td></tr><tr><td>70</td> <td>6.4</td> <td>6.07</td> <td>6.07</td></tr><tr><td>200</td> <td>6.7</td> <td>6.38</td> <td>6.38</td></tr><tr><td>300</td> <td>6.9</td> <td>6.60</td> <td>6.60</td></tr><tr><td>400</td> <td>7.1</td> <td>6.82</td> <td>6.82</td></tr><tr><td>500</td> <td>7.3</td> <td>7.02</td> <td>7.02</td></tr><tr><td>600</td> <td>7.4</td> <td>7.23</td> <td>7.23</td></tr><tr><td>700</td> <td>7.6</td> <td>7.44</td> <td>7.44</td></tr><tr><td>800</td> <td>7.8</td> <td>7.65</td> <td>7.65</td></tr><tr><td>900</td> <td>7.9</td> <td>7.84</td> <td>7.84</td></tr><tr><td>1000</td> <td>8.1</td> <td>7.97</td> <td>7.97</td></tr><tr><td>1100</td> <td>8.2</td> <td>8.12</td> <td>8.12</td></tr><tr><td>1200</td> <td>8.3</td> <td>8.19</td> <td>8.19</td></tr><tr><td>1300</td> <td>8.4</td> <td>8.28</td> <td>8.28</td></tr><tr><td>1400</td> <td>8.4</td> <td>8.36</td> <td>8.36</td></tr></table>
I don't want to say the codes are diverging, its just that with this edition, B31.1 made a change. We'll have to wait and see what the next B31.3 does.
Posted by: Samuel
Re: B31.3/31.1 - New edition - 11/05/02 10:48 AM
Hi, Richard:
I have two questions about using new expansion data on current CAESAR II as you recommended:
1. How to input xx.x 10-6 data at the Temperature?
2. As such, where to input the actual piping design temperature? So that the program can calculate the actual expansion.
Best Regards,
Posted by: Richard Ay
Re: B31.3/31.1 - New edition - 11/05/02 11:18 AM
Samuel,
You don't want to input the expansion coefficient as "xx.x 10-6". Rather, you want to obtain the coefficient from the code <em>at your temperature</em> (which will be xx.x 10-6), multiply this value by <em>your delta T</em> to obtain the expansion coefficient in units of <em>length/length</em>. This is the value you want to input into the temperature field in CAESAR II.
You can find details on this if you put the cursor in one of the temperature fields, and press [F1].
Posted by: Ohliger
Re: B31.3/31.1 - New edition - 11/11/02 08:29 AM
the secod question from Samuel :
2. As such, where to input the actual piping design temperature? So that the program can calculate the actual expansion.
The design temperature will only be need to destination for the allowable stress.
With the operating temperature destinated the
alpha coefficient.
Never the less how is the temperature input by Caersar2 for the allowable stress ?
Posted by: Edward Klein
Re: B31.3/31.1 - New edition - 11/11/02 09:34 AM
In the case where you are inputing expansion coefficients instead of the temperature, I'm pretty sure you're going to have to manually put in the allowable stress from your code book at the temperatures you want to review.
Posted by: Richard Ay
Re: B31.3/31.1 - New edition - 11/11/02 01:41 PM
Ed is correct. If you manually specify the expansion coefficient, you must also manually specify the allowable stress for that temperature.