If you work with valves, flanges, or pipe fittings, you’ve likely come across the term . Developed by the Manufacturers Standardization Society (MSS)
| Plate | Irregularity Type | |-------|------------------| | A | Shrinkage | | B | Gas porosity | | C | Sand inclusions | | D | Cracks / cold shuts | | E | Surface pitting | mss sp55 standard pdf work
Many inspectors only look at the surface footprint of a pit. The standard also implies depth relative to the casting wall thickness. A shallow pit 1/4" wide might be acceptable, but a deep pit of the same width could be a reject. If you work with valves, flanges, or pipe
For each type of irregularity, the standard defines what is "Generally Acceptable" and "Generally Rejectable". If you work with valves