API 570 EXAM STUDY GUIDE [MODULE 9 : PART 3] ASME B31.3

 API 570 EXAM STUDY GUIDE

MODULE 9 : PART 3

ASME B31.3 : PROCESS PIPING

Weld joint quality factor from ASME B31.3, 302.3.4 and Table A-1B

Weld joint quality factor is represented by Ej

The basic factors for straight or spiral (helical seam) welded joints for pressure containing components are given in Table A-1B. With additional NDE, Ej can be increased and the same is given in Table 302.3.4; Longitudinal weld joint quality factor

In above table it is specifically written in the ‘NOTE: (1) that for Sl.. No: 1 & 2 even if we use any additional NDE methods Ej is not permitted to be increased.

Different configurations of longitudinal weld and the ways to achieve various Ej values are given in this table.

Basic quality factors for longitudinal weld joints in pipes and tubes are given in Table A-1B

A snap shot of Table A-1B is given below

Questions and Answers:

1. What is the value of Ej for a spot radiographed A53 Type E pipe?

In Table A-1B the value for A53 Type E is 0.85. In Table 302.3.4 also it is given as 0.85 and in the note given below the Table 302.3.4 it is given that even by additional NDE the Ej shall not be increased. So Ej for A53 Type E pipe is 0.85

For EFW(Electric Fusion Welded) pipe Ej can be increased by additional NDE.

For ERW (Electric Resistance Welded) pipe Ej cannot be increased by additional NDE.

For seamless pipe Ej is 1.00

It is better to remember the Ej values in Table 302.3.4

It can be remembered in this manner. 

For EFW, 3 values are to be remembered. In EFW for 100% RT, Ej is 1.00 for Spot radiography 0.90. Then in EFW single butt weld Ej is 0.80 and for double butt weld 0.85.

For furnace but weld Ej is 0.60 and for ERW Ej is 0.85

For API 5L EFW pipe Ej is 0.95 and after 100% radiography it will be 1.00

This is a general method of remembering and students can use their on methods.