Last Update: 2022.7
First Release: 2021.9
General Info
Description: This defaults to ‘External Loads <#>' and is used in the External Loads Browser and in the report selection.
Code: The options here are ASME Section VIII, Division 1 or Division 2. This defaults to ASME Section VIII, Division 1
Code Year: This includes code years 2010 through 2021. This defaults to 2019.
System of Units: This is currently limited to Customary.
Design Info
Material Group: The B16.5 and B16.47 standards organize materials into material groups in order to assign pressure temperature ratings. All materials in the same material group will have the same pressure temperature ratings. This defaults to 1.1.
Type: Select a flange type from those in the B16.5 and B16.47 standards. Weld Neck Series A and B as well as Blind Series A and B are the large size flanges from B16.47. This defaults to Weld Neck.
ASME Class: The ASME rating class from the B16.5 and B16.47 standards. This defaults to 300.
Size: Select a flange size. B16.5 covers flange sizes up to 24 inches; B16.47 covers flanges up to 60 inches. This defaults to 12.
B16.5 Reference: This is the ASME B16.5 year of reference that is used when evaluating flanges 24 NPS and smaller. When “Per Table U-3/Table 1.1” is selected, the year of reference is determined by Table U-3 for ASME Section VIII, Division 1 construction and the year of reference is determined by Table 1.1 for Division 2 construction; these tables are used in conjunction with the code year to determine the year of the reference. This defaults to “Per Table U-3/Table 1.1”.
B16.47 Reference: This is the ASME B16.47 year of reference that is used when evaluating flanges 26 NPS and greater. When “Per Table U-3/Table 1.1” is selected, the year of reference is determined by Table U-3 for ASME Section VIII, Division 1 construction and the year of reference is determined by Table 1.1 for Division 2 construction; these tables are used in conjunction with the code year to determine the year of the reference. This defaults to “Per Table U-3/Table 1.1”.
G: The gasket reaction diameter in inches. This defaults to 15 inches.
C: The bolt circle in inches. This defaults to 17.75 inches.
Ab: The total bolt area in inches^2. This defaults to 11.088 inches^2.
Loading Conditions
T: This is the temperature for the condition under consideration. It defaults to 0 °F.
P: This is the internal pressure for the condition under consideration. It defaults to 1 psi.
Static Head: This is the static head for the condition under consideration. It defaults to 0 psi.
FE: This is external axial load on the flange for the condition under consideration and is not due to pressure. It defaults to 0 lbf.
ME: This is external moment on the flange for the condition under consideration and is not due to pressure. It defaults to 0 lbf-in.
Sa: This is the allowable bolt stress at ambient temperature for the condition under consideration. It defaults to 18800 psi.
Sb: This is the allowable bolt stress at ambient temperature for the condition under consideration. It defaults to 18800 psi.
Sy: This is the flange yield strength for the condition under consideration. It defaults to 36000 psi.
In Time Dependent Range: This tells the math if the condition is in the time dependent (creep) range or not. This defaults to unchecked (not in the time dependent range).
Scope
This method supports the evaluation of B16.5 and B16.47 Rated Flanges for the combination of internal pressure, axial loads, and bending moments. A flange can be evaluated for multiple loading conditions.
Method Basis
The uses the following methods: B16.5 and B16.47 Pressure Temperature Ratings, the William Koves method described in the 2005 PVP paper Design for Leaking in Flange Joints Under External Loads, the classical Kellogg Effective Pressure Method and UG-44(b) from ASME Section VIII, Division 1.
The software determines which methods are applicable based on their scope. This is done for each loading condition. The most favorable method, resulting in the highest MAWP under the loadings considered, that is also in scope, will be used to evaluate the loading condition.
The output will show one of four methods listed for each loading condition:
Pressure Only
Koves
UG-44(b)
Kellogg
Pressure Only: This applies when no external loads are listed for the loading condition. This will simply determine the pressure rating based on the the applicable reference and the temperature for the loading condition. This pressure rating is also used in the other three methods.
Koves: This applies only for B16.5 flanges (Size <= 24”) and can consider pressure and moment. This is more favorable than UG-44(b) or Kellogg as it does not reduce the allowable pressure of the flange to less than the pressure rating. However, the other two may be employed still if the moment is deemed not acceptable.
UG-44(b): This applies only to Weld Neck, Weld Neck Series A and Weld Neck Series B flanges. It can consider pressure, positive axial load and moment. This is typically more favorable than the Kellogg method as the use of the FM term will result in a lower or zero reduction in the pressure rating while under the additional loads. A check is in place to prevent the application of the external loads from increasing the pressure rating.
Kellogg: This method may be used for all the sizes and flange types. It can consider pressure, axial load and moment. This is typically the least favorable of all the methods and is likely to have the biggest reduction in pressure rating under the additional loads. A check is in place to prevent the application of the external loads from increasing the pressure rating.