Common Quality Issues of Stainless Steel Pipe Fittings

       Stainless steel pipe fittings, known for their corrosion resistance and high pressure resistance, are extensively used in various industries such as petroleum, chemical, papermaking, shipbuilding, and electric power. However, during the application process, certain quality problems may arise.

1. Use Environment and Fluid Type

      Stainless steel is not entirely immune to corrosion. While it is resistant to rust at room temperature under normal conditions, special environments or the flow of specific fluids may require the use of different grades of stainless steel to ensure optimal corrosion resistance and longevity.

      For neutral fluids or non-corrosive liquids, 304 stainless steel is typically sufficient. However, for weak acid transmission, it is advisable to use 304L or better materials. In cases of heavy salt content like seawater transmission, 316L material is recommended. For strong acid transmission, super duplex stainless steel material should be chosen.

2. Heat Treatment (Solution)

      In addition to selecting the appropriate material with the right nickel and chromium content, the solution step is crucial.

      After cold-pressed pipes are processed into fittings, they undergo plastic deformation, disrupting the molecular balance and accumulating internal stress, which must be eliminated through solid solution treatment.

3. Welding Effect

   Large-sized butt-welded pipe fittings are formed by pressing steel plates and welding them to create elbows, tees, and other shapes. The welding current is a key parameter, and post-weld treatment of the weld is equally important.

4. Material Selection

     The selection of subpar materials is a significant factor contributing to pipe fitting problems.