The manufacturing process of stainless steel pipe fittings mainly includes the following:
Raw Material Preparation: High-quality round tube blanks are selected as raw materials, and they are cut into billets about 1 meter in length by a cutting machine.
Heating: The round tube blanks are sent into a furnace for heating. The temperature is approximately 1200 degrees Celsius, and the fuel used is either hydrogen or acetylene.
Piercing: The heated round tube blanks are pierced using a pressure piercing machine to form rough tubes.
Rolling: The rough tubes undergo three-roll skew rolling, continuous rolling, or extrusion to further form steel pipes.
Sizing and Cooling: The steel pipes, after going through a sizing mill, are sent into a cooling tower for water spray cooling.
Straightening and Inspection: The cooled steel pipes are straightened and inspected for internal defects using a metal flaw detector or hydrostatic test to ensure quality.
Marking and Storage: Quality-approved steel pipes are marked with paint to indicate their number, specification, production batch number, etc., and are moved to the warehouse by a crane.
Raw Material Preparation and Heating: Similar to the hot rolling process, round tube blanks are selected as raw materials and heated.
Piercing and Head Forming: The heated round tube blanks are pierced by a piercing machine and then undergo head forming to prepare for the cold drawing process.
Annealing and Pickling: The head-formed steel pipes undergo annealing to relieve stress, followed by pickling to remove surface oxide scales and impurities.
Oiling and Cold Drawing: The pickled steel pipes are oiled and then go through multiple stages of cold drawing (cold rolling) to change the pipe size and length.
Heat Treatment and Straightening: The cold-drawn steel pipes are heat treated to restore material plastication, followed by straightening.
Inspection and Packaging: The finished steel pipes undergo strict quality inspection and testing, including appearance inspection, size inspection, pressure testing, etc. Once qualified, they are packaged and stored.
For stainless steel welded pipes (seam pipes), the welding process is employed for manufacturing. Common welding methods include TIG (Tungsten Inert Gas welding) or high-frequency welding technology. The welding process requires strict control of temperature and welding speed to ensure the quality and stability of the welds. The weld joints should be smooth, free of cracks, and free of slag inclusions. After welding, further processes such as hot rolling or cold rolling are necessary to eliminate stress concentrations and structural changes caused by the welding process.
Apart from hot rolling, cold drawing (rolling), and welding processes, the manufacturing of stainless steel pipes also includes forging methods, roller methods, stamping methods, bending forming methods, rolling methods, and bulging methods. These methods are mainly used to produce specific shapes and sizes of stainless steel pipe fittings, such as elbows, tees, crosses, etc.
Polishing: After forming, the pipes are polished using a polishing machine to meet different customer requirements.
Inspection and Marking: The finished steel pipes undergo strict quality inspection and testing, including appearance inspection, size inspection, pressure testing, etc., to ensure they meet relevant standards and customer requirements. Qualified stainless steel pipes and stainless steel pipe fittings are marked and recorded for tracking and management purposes.
The above are the main manufacturing processes of stainless steel pipe fittings. These processes can produce high-quality stainless steel pipes and fittings to meet the demands of various application scenarios.
