US Standard Pressure Grade of Carbon Steel Pipe Flanges

American standard carbon steel pipe flange is mainly divided into pressure grades according to the ANSI/ASME B16.5 standard. This standard divides the pressure grades into different levels, mainly based on the working pressure that the flange can withstand in the pipeline system, while taking into account the impact of factors such as temperature on the performance of the flange.

These pressure grades are divided to ensure the safety and reliability of the flange under various working conditions, and can be easily matched with pipeline systems with different pressure requirements. The following are specific pressure grade classifications and ranges:

Class 150:

This is a relatively common lower pressure grade. At room temperature, its maximum allowable working pressure is relatively low, and it can withstand a pressure of about 1.93-2.07MPa (the allowable pressure of flanges of different sizes is slightly different). It is mainly used in some low-pressure non-critical pipeline systems, such as ordinary water supply and drainage systems, low-pressure steam transmission systems, etc. For example, in the steam heating system of some small factories, if the steam pressure is low, the use of Class 150 carbon steel pipe flanges can meet the requirements.

Class 300:

The pressure bearing capacity is improved. At room temperature, the maximum allowable working pressure is about 5.17 - 5.52MPa. It is suitable for medium and low pressure chemical, petroleum and other industrial pipeline systems, such as pipelines that transport some oil products or chemical raw materials with moderate pressure. Taking the crude oil pipeline of the refinery as an example, if the pressure of some pipelines is not particularly high, the use of Class 300 flanges can effectively connect the pipelines and ensure safety.

Class 400:

Its pressure grade is between Class 300 and Class 600. At room temperature, the maximum allowable working pressure is about 6.89 - 7.58MPa. Flanges of this pressure grade are used in some specific industrial occasions, such as pipeline systems in chemical plants that transport some corrosive media that have certain pressure requirements but do not reach the Class 600 pressure grade.

Class 600:

It belongs to a higher pressure grade. The maximum allowable working pressure at room temperature is about 10.34 - 11.03MPa. It is often used for pipeline connections in high-pressure chemical, petrochemical and other fields, such as in high-pressure natural gas transmission pipeline systems, or in the pipeline section that transports high-pressure reaction materials in chemical plants.

Class 900:

Higher pressure bearing capacity. The maximum allowable working pressure at room temperature is about 15.51 - 17.24MPa. It is used in some pipeline systems that require higher pressure and more special media, such as in high-temperature and high-pressure synthetic ammonia plants, some pipelines need to use Class 900 flanges to ensure the safe and stable operation of the system.

Class 1500:

This is a very high pressure rating. The maximum allowable working pressure at room temperature is about 25.86 - 29.31MPa. It is usually used for ultra-high pressure industrial pipeline systems, such as pipeline connections in extreme high-pressure environments such as ultra-high pressure hydrocracking units.

Class 2500:

It is one of the highest pressure grades in the American standard flange. The maximum allowable working pressure at room temperature is about 42.41-47.63MPa. It is mainly used in special industrial pipeline systems with extremely high pressure requirements, such as some high-pressure pipeline connections in deep-sea oil production, or pipeline connections in some ultra-high pressure experimental devices.

Summary

In short, the pressure grades of American standard carbon steel pipe flanges divided according to the ANSI/ASME B16.5 standard mainly range from Class 150 to Class 2500, which are suitable for different working environments and requirements. When purchasing, you should consult the relevant flange supplier according to specific needs and choose the appropriate pipe flange to ensure the safety and normal use of the pipe flange.