In the oil and gas agencies, chemical industry, and water treatment industries, stainless steel flanges are used to join the pipe, valves, and other equipment. These flanges are available in different types of flanges and overall materials. However, steel flanges, most especially stainless steel flanges, are mostly used because of their relatively superior resistance to corrosion and improved toughness. In this article, you will be able to explain how to classify stainless steel flanges as follows.

1. Class and Pressure Ratings:

The first feature that can be applied to the stainless steel pipe fittings in the differentiation process is the class and pressure category. Stainless steel flanges are classified according to the ASME B16.5 standard, which defines four pressure-temperature ratings: Hinges of 150X3, 300X2, 400X1; two of 600 and 900; and one of 1500 and 2500. The rating is a number followed by the letters ‘LBS’ denoting pounds per square inch ‘psi’ or a ‘D’ indicating megapascals ‘MPa.’ It was again observed that as the rating increases, the flange is able to take more pressure. 

2. Face Type:

The face type is yet another crucial factor that must be taken into consideration when choosing stainless steel flanges. The two primary face kinds are flat face (FF) and raised face (RF). There are the long-nosed face duplex flanges where Prof. Cylindrical's raised face flanges are where there is a raised area provided at the center of the sealing surface. Metal Flat face flanges where there is no raised area on the sealing surface. Depending on the application, different face types will be required, while the type of gasket also requires some decision-making.  

3. Bolting Pattern:

The bolting pattern is another piece of information that has to be taken into consideration, and it is the question of a stainless steel flange. Bolting pattern refers to the placement of bolt holes in the flange, and there are a few usual patterns, which include standard, large, small, and reduced. Duplex plate suppliers will look after the geometry of the flange, including thickness and outside diameter, and define the bolt circle, while the different application types have to be considered when choosing the bolting circle. 

4. Material Grade:

It has been determined that the stainless steel flange's material grade is another important identifying factor. Stainless steel flanges are categorized into different classes, common ones being SS 304 flanges, 304L, SS 316 flanges, and SS 316L flanges. The grade is the combination of the steel's constituent parts that distinguishes the material's ability to withstand corrosion from its degree of hardness. 

Major Takeaway

It is essential to understand various classifications of stainless steel flanges based on class and pressure ratings, face type, bolting patterns, diameter size, and material grade. By evaluating these aspects, you can choose the right SS 304 pipe fittings for your application to ensure the right performance of your piping technique.