Butt welding elbow is the use of high-quality steel plate by stamping die stamping into half a block ring bend or use of casting mould cast directly into half a block ring bend, then the two semi ring elbow group of welding forming, so butt welding elbow, also known as welding elbow. Butt welding elbow the corresponding process fabrication and welding, forming good production standards and performance, fully display the important performance using the corresponding materials.
Butt welding elbow’s material is the core of the field of new materials, the development of high and new technology plays an important role in promoting and supporting, in the global research in the field of new materials, wear-resistant materials accounted for about 85%. Butt welding elbow in the use of the process should be kept clean, the screw thread transmission must be lubricated periodically, find fault, should immediately stop using the clear identification of the reasons for failure. Stamping welding elbow used to connect the two nominal diameter of the same pipe, so that the pipe to make a 90 degree turn.
Butt welding flange‘s joint sealing material asbestos rubber sheet
Asbestos rubber sheet as a universal gasket, do not consider the use of a wide range of conditions. Actually, asbestos rubber sheet is will asbestos fiber and different rubber and other adhesive mixing after pressing, is a porous non-metallic materials, and with different varieties and the ratio of composition, the variation of performance is great.
In fact, foreign use of asbestos rubber plate with strict restrictions, such as the provisions of the United States DuPont flammable materials must not use asbestos rubber sheet, because in the event of fire, the asbestos rubber plate butt welding flange joint is difficult to guarantee not to produce secondary leakage. Japan “petroleum industry standard for asbestos rubber plate” provisions of flammable and toxic gases using asbestos rubber plate for 0~260 DEG C, is less than or equal to 1.0 MPa, water, air, water vapor, -50~260 DEG C, is less than or equal to 3.0 MPa. Moreover, the foreign standard of asbestos rubber plate performance requirements than domestic similar products to high.
Thick pads are better than thin spacers. In fact, asbestos rubber sheet is a porous material, the thicker the gasket, the permeability is high, in order to ensure a high seal must be greater than the shim the pressing force is applied to the core part of the leakage rate is reduced, so the thick gasket is larger than the pressing force of the shim. For large molecules such as water, the leakage rate of the core part of the gasket is very small, and the thickness has little effect. Usually only the spacer flange diameter is large, consider the use of sealing surface waves or buckling at. The thickness of the general use of 0.81, 0.6, 3.2mm.
Source: Yaang Pipe Industry Co., Limited (www.yaang.com)