Material Specification
1.Parameters to Determine the Specification
-Material
-Mechanical Design
-Manufacturing Process
-Shape/Dimensions
2.Wall Thickness Calculation
2.1.Considerations for pipe wall thickness calculation
a.Based on PT-rating (NPS 12 to 16)
-Critical point
-Full flange rating
b.Actual design conditions (NPS 18 and larger)
c.External pressure (vacuum condition, use BPV)
d.Buried piping (use AWWA)
e.Advance considerations
-Comparison of allowable stress of pipe and fittings
-Comparison of PT-rating of valves and flanges
2.2.Procedure for pipe wall thickness calculation
-Select appropriate formula
-Determine Y from Table 304.1.1
-Determine Joint Quality Factor, Ej, from Table 302.3.4 and Table A-1B
-Determination of critical point
-Calculate the minimum required thickness
-Consider mill tolerance
-Select commercially available thickness
