In order to meet the customer's needs, the inspector carries out the final inspection and test on the finished products according to the product standard executed by the customer order. According to the requirements of the standard, the chemical composition from the blank to the finished product is analyzed, the material quality is strictly controlled, the mechanical properties of the finished product, chemical composition are tested item by item, and eddy current and ultrasonic nondestructive testing are carried out to ensure the product quality. According to the technical conditions and requirements of the product standard, the inspector inspect on the inside and outside surface of the finished product, the shape of the end, the bending degree, the length of the fixed length, the outside diameter and the wall thickness. After the product inspection is qualified, issue the product quality Instructions, and ensure the customer to use the satisfied and assured products.