Precautions when using stainless steel weld neck flanges

　　Stainless Steel Weld Neck Flange are joined to each other by bolts and are joined to the piping system by welding or threading. We hold a large array of Steel Welding Neck Flanges stock according to ASTM A182, ASME B16.5 dimensional standards. These flanges can be obtained by us in customized sizes and dimension with respect to national and international standards.

　　1.The welding rod shall be kept dry during use. The calcium titanate type shall be dried at 150′C for 1 hour, and the low-a hydrogen type shall be dried at 200-250 ℃ for 1 hour (the drying shall not be repeated for many times, otherwise the skin is easy to crack and peel off) to prevent the welding rod skin, sticky oil and other dirt, so as to avoid increasing the carbon content of the weld and affecting the quality of the weldment.

　　2.During welding of stainless steel weld neck flange and Stainless Steel pipe fittings, carbides are precipitated by repeated heating, which reduces corrosion and mechanical properties.

　　3.The hardened American standard flange of chrome stainless steel flange pipe fittings after welding is large and easy to crack. If the same type of chromium stainless steel electrode (G202, G207) is used for welding, preheating above 300 ℃ and slow cooling treatment around 700 ℃ after welding are required. If the weldment cannot be subject to post-weld heat treatment, stainless steel flange pipe electrode (A107, A207) shall be selected.

　　4.For stainless steel flange, proper amount of stability elements such as Ti, Nb and Mo are added to improve the corrosion resistance and weldability. The weldability is better than that of chrome stainless steel flange. When the same type of chrome stainless steel flange welding rod (G302, G307) is used, preheating above 200 ℃ and tempering around 800 ℃ after welding shall be carried out. If the weldment cannot be heat treated, stainless steel flange pipe electrode (A107, A207) shall be selected.

　　5.stainless steel weld neck flange pipe fittings and butt-welding flange welding rods have good corrosion resistance and chemical resistance, and are widely used in chemical, fertilizer, petroleum and machinery manufacturing.

　　6.In order to prevent eye-to-eye corrosion caused by the heating of the flange cover, the welding current should not be too large, about 20% less than that of the carbon steel electrode, the arc should not be too long, and the inter-layer cooling should not be slow, and the narrow weld bead should be preferred.

　　stainless steel weld neck flange should be away from corrosion of stainless steel materials.For stainless steel flanges, it is most important to keep the flange surface clean.Once the surface of the stainless steel flange is corroded, the appearance of the stainless steel flange will change, no longer smooth.Whether acid or alkaline gas or liquid, should be kept away from the production environment of stainless steel flange.