The usual problems are in the paperwork
Flanges and fittings are often bought from trading companies that consolidate stock from several factories. The risk is that the certificate on file is for a different heat, or that items are re-marked. Our inspectors check marking, certificates and PMI readings item by item, so each piece can be traced to its heat.
Where flanges and fittings are made in China
Hebei province around Cangzhou (Mengcun and Yanshan counties) is the main centre for butt-weld fittings and flanges. Dingxiang in Shanxi is known for forged flanges and rings, and Wenzhou for stainless fittings. Tell us the factory address and we will confirm coverage.
Non-conformances we find most often
- Raised-face finish outside the roughness range required by ASME B16.5.
- Elbow wall thinned at the extrados below the minimum thickness.
- Flange bore not matched to the pipe schedule on the PO.
- Hardness above the NACE MR0175 limit for carbon steel in sour service.
- Heat number missing from the marking or not on the certificate.
- Laminations or laps found in forgings.
Questions buyers ask
Do you check the flange face finish?
Yes. The inspector measures surface roughness on raised faces and ring grooves with a roughness comparator or profilometer and compares it with the range in ASME B16.5 or the PO.
Can you inspect a mixed order of flanges and fittings from several factories?
Yes. Trading companies often consolidate items from several plants. We inspect at each plant or at the consolidation warehouse, and report traceability item by item.
How do you check fittings for wall thinning?
We measure wall thickness with an ultrasonic gauge at the extrados, intrados and ends of a sample of elbows and tees, then compare readings with the minimum wall for the schedule.