Applies To
Product(s):	AutoPIPE
Version(s):	2004, XM, V8i, CONNECT;
Environment:	N/A
Area:	Calculation
Original Author:	Bentley Technical Support Group
Date Logged & Current Version	Aug. 2016 10.01.00.09

Problem:

For calculation of ASME NB Bend Stiffness and Pressure stress around a bend, does AutoPIPE use the Bend / Elbow properties (O/D and t) or the preceding pipe properties (O/D and t)? colored Red in image below?

Solution:

Based on the previous problem / solution WIKI here, Bend stiffness is inversely proportional to the bend flexibilities. Since AutoPIPE calculates bend flexibilities based on properties specified for the bend, one can say that the stiffness is also updated. As the flexibility increases, the stiffness of the bend will decrease accordingly.

To specifically answer the questions:

1. Properties from the pipe identifier used for the bend are utilized for calculating stiffness matrix and flexibility factor for the bend

2. Assuming the user is referring to the pressure term like "B1*P*D/(2*t)" as in equation 9: For the negative face of a bend near point (like A01 N-), the pipe properties for the preceding pipe ID are used for these calculations. For the positive face of a bend near point (like A01 N+), the pipe properties from the pipe ID for the bend are used for these calculations. Similarly, for bend far point: A01 F- will use pipe properties from bend pipe identifier, and A01 F+ will use pipe properties from the pipe identifier of the following pipe. See picture below.

Q. For calculation of ASME NB Bend Stiffness and Pressure stress around a bend, does AutoPIPE use th

Problem:

Solution:

See Also