GB-T14976 Stainless Steel Seamless Pipe For Fluid Transportation
This standard specifies the dimensions, shape, technical requirements, test methods, inspection rules, packaging, signs and certificate of the stainless steel seamless steel pipe for fluid transportation.
This standard applies to stainless steel seamless pipe for fluid transportation
Steel pipes are divided into two categories according to product processing methods.
The categories and codes are: hot rolled steel pipes (WH) and cold drawn steel pipes (WC).
Steel pipes are divided into two grades according to their size: ordinary grade (PA) advanced (PC)
Steel pipes are generally delivered in normal length, usually in length as follows
Hot rolled steel pipe: 2 000 mm~12 000 mm;
Cold drawn steel pipe: 1 000 mm to 10 500 mm.
Dimension tolerance for GB/T14976 stainless steel seamless steel pipe
Table 1 Outer diameter and wall thickness tolerance of GB/T14976
| Hot rolled steel pipe
|| Cold drawn steel pipe
|| Tolerance /mm
||68 ≤ OD ≤ 159
||6 ≤ OD < 10
|10 ≤ OD ≤ 30
|159<OD ≤ 426
||30<OD ≤ 50
Table 2 length tolerance of GB/T14976
|Note: The tolerance level is not indicated in the contract and is performed according to the tolerance class L1.
Glutinous rice curvature
The bend per meter of steel pipe shall not be greater than the following: ‘
Wall thickness <15 mm, 1. 5 mm/m
Wall thickness >15 mm, 2. 0 mm/m
Thermal expansion tube 3. 0 mm/m.
The end faces of the steel pipe should be perpendicular to the axis of the steel pipe and the burrs should be removed.
Items of Testing
The steel pipe shall be hydraulically tested one by one.
Steel tubes with a wall thickness of not more than 10 mm shall be subjected to a flattening test, and cracks and cracks shall not be allowed after the sample is flattened.
A steel pipe having a wall thickness of less than or equal to 10 mm can be subjected to a flare test. The top taper of the flare test is 30′, 45. Or 60. One of them, the expansion of the outer diameter after the flare is 100,.. After the flare, the specimen shall not have cracks or cracks.
Intergranular corrosion test
Austenitic and austenitic-ferritic steel tubes can be tested for intergranular corrosion.
The intergranular corrosion test method is in accordance with the provisions of GB/T 434.1-43. The specific corrosion test method is agreed by the supplier and the buyer and stated in the contract. If it is not clear, it shall be carried out in accordance with the test of GB/T434.5.