B16.34 Xray tables % ASTM E-446
B16.34 Xray tables % ASTM E-446
(OP)
Howdy all,
According to B16.34 there are 3 tables that define an acceptable casting, the tables are divided up by wall thicknesses . I am required to meet is Table I-1 for valves under 2" thick (page 100 in 2004 version). The table specifies gas porosity up to level 2, sand level 3, CA shrinkage lvl 2, etc.
My customers refer to castings that meet this table as level 3 castings. What are the other levels based on? Is there a table for it, API-6D maybe?
Any clarification would be great. Because every Xray tech I know just use the table in B16.34
thx friends!
PS - Does anyone have a scanned copy of ASTM E446 they can share. I have pages 707 - 710 but its from 1984!!
According to B16.34 there are 3 tables that define an acceptable casting, the tables are divided up by wall thicknesses . I am required to meet is Table I-1 for valves under 2" thick (page 100 in 2004 version). The table specifies gas porosity up to level 2, sand level 3, CA shrinkage lvl 2, etc.
My customers refer to castings that meet this table as level 3 castings. What are the other levels based on? Is there a table for it, API-6D maybe?
Any clarification would be great. Because every Xray tech I know just use the table in B16.34
thx friends!
PS - Does anyone have a scanned copy of ASTM E446 they can share. I have pages 707 - 710 but its from 1984!!





RE: B16.34 Xray tables % ASTM E-446
All of the casting defect levels are based upon reference radiographs published in the E446 reference radiograph comparative plates books. These radiograph books are what are referenced in the E446 standard. The last time we bought any reference radiograph books they were about $1200 (us dollars) each. They contain actual radiographs so they are very difficult to copy.
As for general valve casting acceptable radiographic quality standards, both MSS and API are working documents that address this issue.
Greg Johnson
RE: B16.34 Xray tables % ASTM E-446
Now I understand what they mean by a level 2 casting, but they should be careful. By that logic a "level 3" casting could include CA3 shrinkage, or A3 Gas Porosity, both of which would not meet B16.34.
RE: B16.34 Xray tables % ASTM E-446
RE: B16.34 Xray tables % ASTM E-446
MSS is a whole other ball of wax. It is frustratingly subjective. It's easy enough to spot sand or gas and grind it out, but visually identifying a hot tear or surface shrinkage is hard and time consuming, even with the use of the SP55 manual. In SP55 D and E cracks are easy to identify, but type C is easy to miss when compared to the acceptable type A or B veining.
In respect to surface quality I think the biggest difference between "commodity" and special class is the amount of sand blasting performed at the foundries. Wouldn't you agree?