Applies To
	Product:	AutoPIPE
	First Affected Version:	09.02.01
	Found in Version:	09.02.01.07
	Fixed and Released in Version:	09.03.00.08
	Area:	Calculations
	Severity:	Critical
	Backlog Issue Number:	135691 (8590)

Problem Description

C2 should not be set to 1.0 when t < 0.237 in. for NC/ND 2001 and later editions

Reason

For an as-welded girth butt weld, the C2 index is always reported as 1.0 and used in the ASME NC/ND 2001 or later stress calculations. The C2 stress index is used when reversing dynamic is selected for Service Levels C or D. According to section NB-3683.4(b), C2 should be set equal to 1.0, unless the pipe wall thickness, tn, is less than 0.237 in. If the pipe wall thickness, tn, is less than 0.237 in. then C2 = 1.0 + 0.094/tn.

The following considerations are provided below to assist in your evaluation of the potential impact of this defect on the results.

1. Evaluate whether this defect has affected any existing models by considering the criteria below.

a) Was the model built in AutoPIPE version 9.2 or later?

b) Was the code used, ASME NC/ND 2001 or later?

c) Is Service Level C or D, with reversing dynamic selected as the stress summary?

d) Does the model have an as-welded girth butt weld inserted at any point?

e) Is the pipe wall thickness, tn, at the location of the as-welded girth buttweld less than 0.237 in.?

A ‘No’ to any of the above criteria means that this defect does not affect the model’s results. No further consideration for this model is necessary.

Solution:

Set C2 equal to 1.0 + 0.094/t, when an as-welded girth butt weld is inserted, where the pipe wall thickness is less than 0.237 in., for all ASME Nuclear codes using
the 2001 edition or later.

Avoidance:

None

Also See:

Critical and High issues released in AutoPIPE V8i v.09.03..