US standard pressure grade of carbon steel pipe flanges

American Standard carbon steel pipe flanges are classified into various pressure grades according to the ANSI/ASME B16.5 standard. These classifications are based on the flange's capacity to withstand the working pressure in a pipeline system, with additional considerations for factors such as temperature impacts on performance. The purpose of these pressure grades is to ensure the safety and reliability of flanges under different working conditions, allowing for seamless integration with pipeline systems requiring various pressure levels. Below are the specific pressure grades and their respective ranges:

Class 150:

Class 150 is one of the most common lower pressure grades. At room temperature, it can withstand a maximum working pressure of approximately 1.93 to 2.07 MPa, with slight variations depending on the flange size. This grade is typically used in low-pressure, non-critical systems such as basic water supply and drainage or low-pressure steam systems. For example, in small factory steam heating systems with low steam pressure, Class 150 flanges are a suitable choice.

Class 300:

Class 300 flanges offer improved pressure resistance. At room temperature, their maximum working pressure is about 5.17 to 5.52 MPa. These flanges are ideal for medium and low-pressure industrial applications, such as chemical and petroleum pipeline systems. For instance, in a refinery's crude oil pipeline, where the pressure is not excessively high, Class 300 flanges ensure a reliable and secure pipeline connection.

Class 400:

Class 400 flanges sit between the Class 300 and Class 600 pressure grades. With a maximum working pressure of around 6.89 to 7.58 MPa at room temperature, these flanges are used in specific industrial applications, such as chemical plants transporting moderately pressurized corrosive media, where Class 600 flanges would be over-engineered.

Class 600:

Class 600 flanges are considered high-pressure components, capable of withstanding a maximum working pressure of about 10.34 to 11.03 MPa at room temperature. These are commonly used in high-pressure applications, including chemical, petrochemical, and natural gas transmission pipelines, as well as chemical plant systems that deal with high-pressure reaction materials.

Class 900:

Flanges of Class 900 are designed for even higher pressure capacities, with a maximum allowable working pressure of 15.51 to 17.24 MPa at room temperature. These are used in specialized systems such as high-temperature and high-pressure ammonia plants, where flanges must endure both extreme conditions and demanding media.

Class 1500:

Class 1500 represents a very high-pressure grade, with a maximum working pressure of 25.86 to 29.31 MPa at room temperature. These flanges are commonly employed in ultra-high-pressure industrial systems, including those found in hydrocracking units within refineries, where the pressure requirements are extreme.

Class 2500:

Class 2500 is one of the highest pressure grades for American standard flanges. With a maximum working pressure of about 42.41 to 47.63 MPa at room temperature, these flanges are used in systems requiring exceptional pressure resistance, such as deep-sea oil production pipelines or ultra-high-pressure experimental apparatus.

Summary

In conclusion, American Standard carbon steel pipe flanges are categorized from Class 150 to Class 2500 according to the ANSI/ASME B16.5 standard. These flanges are designed to meet varying pressure requirements across different industrial sectors, ensuring both safety and efficiency. When selecting a flange, it is important to consult with the appropriate suppliers to choose the correct type based on your specific pressure and application needs to guarantee the integrity and functionality of your pipeline system.

Continental Steel Co., Ltd is professional pipe flange manufacturer, for more details, please contact:sales@cscsteel-manufacturing.com