ASME flanges, a type of components, can be used with gaskets and bolts in piping systems and can be used for connections between pipe ends or between two devices. There are many types of ASME flanges, including threaded ASME flanges, welding neck ASME flanges, slip-on ASME flanges with neck, slip-on ASME flanges with socket welding, flat ring loose sleeve ASME flanges, and lap joint ASME flanges. So how do we choose the right ASME flange?
When using a ASME flange, first determine the ASME flange size, which depends on the nominal diameter and nominal pressure of the ASME flange. The nominal diameter of ASME flanges for pressure vessels is the same as that of pressure vessels in the same series. The determination of the nominal pressure of the ASME flange is related to the maximum operating pressure, operating temperature, and ASME flange material. The ASME flange material specified in the pressure vessel ASME flange standard is low carbon steel, general low alloy steel, and stainless steel. The nominal pressure and maximum allowable working pressure of these materials are different at different temperatures.
In addition to flat and welding neck ASME flanges, there are also cast steel ASME flanges, cast iron flanges, loose sleeve ASME flanges, threaded ASME flanges, etc. in the type of pipe ASME flanges. In addition to national standards, common standards for pipe ASME flanges include the Ministry of Chemical Industry standard and the Sinopec standard. The Ministry of Chemical Industry standard is divided into European and American systems, and the European system is commonly used in China. It is worth noting that the specific dimensions represented by the nominal diameter of the vessel cylinder and pipe are different. Therefore, ASME flanges for vessels and pipes with the same nominal diameter have different sizes, and they cannot be used interchangeably.
When selecting a ASME flange, it should be based on actual usage. For example, for the equipment ASME flange of a vertical vessel, the groove or concave surface should face up, and for a horizontal vessel, the groove or concave surface should be on the cylinder. Therefore, we can choose a flat welding neck ASME flange for equipment ASME flanges, as it belongs to the national standard ASME flange standard system and is one of the commonly used ASME ASME flanges for equipment or pipelines. Its advantages are that it is easy to install on-site and can eliminate the process of weld seam rolling. Alternatively, a welding neck ASME flange with a neck can be selected, which is less prone to deformation and has good sealing effect. It is widely used in pipelines with large fluctuations in temperature or pressure, as well as in pipelines for conveying expensive, flammable and explosive, and toxic gases.
Integral ASME flanges, represented as IF in various Chinese standards, are generally convex (RF) and are often used in high-pressure pipelines. If the working conditions involve flammable, explosive, highly hazardous, and extremely hazardous materials, sealing surfaces other than the RF surface, such as convex-concave surfaces (MFM) and tongue-and-groove faces (TG), can be selected.