The roundness of the eccentric pipe should not exceed 1% of the corresponding outer diameter of the ends, and the deviation is allowed to be ±3mm. The material of the eccentric pipe complies with SY/T5037, GB/T9711, GB/T8163, ASTM A106/A53 GRB, API 5L, APT5CT, ASTM A105, ASTM A234, ASTM A106, DIN German standards, and customer-specified standards for eccentric pipes ( reducers). These are pipe fittings used at pipe transition points for varying diameters. Common forming processes include necking down, expanding, or a combination of both. For certain sizes, stamping forming may also be used.