1. Material Selection: Stainless steel flanges are made from stainless steel material. Material selection is based on the requirements of the application, pressure class, and temperature. Stainless steel is a common choice due to its resistance to corrosion.

2. Design and Engineering: The design of the flange should meet the requirements of the application and be suitable for pipe connections. This design takes into consideration factors such as dimensions, pressure ratings, and connection types (e.g., weld neck flanges or threaded flanges).

3. Cutting and Shaping: Stainless steel sheets or bars are cut and shaped. Special equipment like CNC machines or hydraulic presses may be used for this purpose.

4. Drilling and Machining: The inner and outer surfaces of the flanges are drilled and machined. Drilling is done to create bolt holes and establish the inner diameter.

5. Welding Process: For weld neck flanges, the neck part of the flange is welded to the pipe. This is used to connect the flange to the pipeline. Welding is carried out using suitable welding methods such as TIG or MIG welding.

6. Surface Treatment: Stainless steel flanges can be polished or coated with stainless steel spray to prevent corrosion and improve aesthetics.

7. Testing: The produced flanges undergo quality control tests such as leakage tests and pressure tests. This is done to ensure the durability and reliability of the flange.

8. Packaging and Shipment: Finally, the products are packaged and shipped to the customer. 

The manufacturing of stainless steel flanges can be a complex process and should conform to industry standards. It is also important to pay attention to the manufacturer's quality control and compliance with standards. Proper production and installation of flanges are crucial for the reliability and functionality of the pipeline.