Generally speaking, a Long Weld Neck Flange is an integral self-reinforcing Flange connection that is used primarily in ASME Pressure Vessels. With the Long Weld Neck (LWN) Flange, a Weld Neck Flange and a piece of pipe can be used to make a bolt up connection to the vessel instead of a Weld Neck Flange and a piece of pipe. Stress was transferred from the neck to the base of the structure, where it was connected to the vessel, thanks to this design.The Long https://www.flangeschina.com/weld-neck-flanges" target="_self" style="text-decoration: underline; color: rgb(255, 0, 0); Weld neck pipe flanges  is the most common of the self-reinforced nozzle designs, accounting for approximately 80% of all nozzles. Heavy barrel type nozzles have a thicker neck and are therefore better suited for high pressure and temperature applications. In accordance with ASME B16.5 for pipe sizes 12” to 24” and ASME B16.47 for pipe sizes 26” to 60”, the flange end and sealing face are designed. Typically, the length of the neck increases in proportion to the length of the nominal size and pressure. Typical barrel lengths for the LWN Flange are 9”, 12”, and 16”, but custom barrel lengths can be made to meet the needs of the customer. The standard bore for the LWN Flange is the same as the pipe size, but it can be ordered in any bore. See our post on how to order custom flanges for more information.Material Classifications Long https://www.flangeschina.com/weld-neck-flanges" target="_self" style="text-decoration: underline; color: rgb(255, 0, 0); Weld Neck Flanges are available in the following grades of material: A-105, A182-F304/304L, and A182-F316/316L, but they can be custom made in any alloy. In order to ensure that you receive the correct size, part, and material for your project's requirements, our sales representatives are on hand to assist and guide you through the process.REDUCING FLANGE (also known as a "REDUCER") Reducer flanges, also known as reducing flanges, serve the opposite purpose of the expander flanges described above, namely, they are used to reduce the bore of a pipeline. When it comes to safety, only one or two sizes can be safely reduced from the run pipe's bore (otherwise, an alternative solution that relies on a butt weld reducer in conjunction with a standard flange must be used).Reducing flanges are available in a wide range of sizes and material grades, but they are not always readily available from stock in large quantities. Reducer flanges are designed with the same considerations as expander flanges, including the same specifications, sizes, and material grades.Finally, the so-called spectacle blind, which is not a true flange but rather a ring spacer or spade, is used between pipes to mechanically isolate the pipeline in a quick and simple manner, while still maintaining its appearance. More information on piping can be found in another section of our Wiki dedicated to it.