Product Introduction
Large caliber neck flat welding flange is generally referred to as flat plate or lap welding flange. The connection between the flat welding flange and the pipeline is to first insert the pipe into the flange hole to the appropriate position, and then weld it together. Flat welding flanges are suitable for pipeline systems with relatively low pressure levels, where pressure fluctuations, vibrations, and oscillations are not severe. The advantage of flat welding flanges is that they are easier to align during welding assembly and are relatively inexpensive, thus they have been widely used. Large flat welding flange product specifications DN10-DN2000 with neck flat welding steel pipe flange reference standard from the Ministry of Chemical Industry: HG20593-2009 The other meaning of national standard flanges is: flanges produced according to the size and tolerance range required by national standards, which are different from flanges produced without standard size, also known as second standard flanges (some people call non-standard flanges incorrect). Usually, some unscrupulous merchants will reduce the thickness and outer diameter of the flange to save materials. They also use scrap steel or corner steel to process flanges, which are usually waste materials with chemical composition and mechanical properties that do not meet the standards. Some even use black steel mills to produce flanges. The steelmaking technology used in this private steelmaking is outdated and cannot guarantee mechanical and welding properties. When used, it may not be able to weld with steel pipes, or the steel itself may have cracks, pores, etc. After welding, it may also leak water. So when purchasing flanges, try to choose national standard flanges as much as possible.