ASTM A105 Pipe Flange

Pipe flange is a vital component in the pipeline system, used to connect pipes and maintain their sealing. The material of the pipe flange directly determines its performance and service life. Among the many flange materials, A105 has attracted much attention due to its excellent characteristics and wide application scenarios.

The basic meaning of flange material A105:

A105 flange is a pipe connector made of ASTM A105 forged carbon steel, which complies with the American standard ASME B16.5 and is mainly used for the connection of pipeline systems. It is a commonly used forged carbon steel material with good strength and durability. It is one of the most widely used flange types in industrial pipeline systems.

The main characteristics of A105 material:

1. Good strength and hardness: A105 carbon steel has high yield strength and tensile strength, and can withstand greater pressure and load.
2. Excellent wear resistance: Due to its high carbon content, A105 material has good wear resistance and is suitable for various harsh working environments.
3. Good machinability: A105 carbon steel is easy to forge, cut, weld and other processing operations, and is convenient for making flanges of various specifications and shapes.

Applicable temperature:
Conventional range: -29°C ~ 425°C
Risk of over-limit: Low temperature requires impact test, high temperature may be graphitized (>425°C, it is recommended to use chrome-molybdenum steel).
Pressure level: Covers Class 150 ~ Class 2500 (ASME B16.5 standard).

Why choose ASTM A105 pipe flange?

Advantages:
1. High cost performance: The cost is significantly lower than stainless steel (such as A182 F316) or alloy steel flanges.
2. Reliable mechanical properties: tensile strength ≥485 MPa, yield strength ≥250 MPa, meeting most medium and high pressure requirements.
3. Convenient processing: easy to weld, drill and turn, suitable for quick installation.
4. Strong versatility: widely used in non-corrosive media systems such as oil, natural gas, electricity, and water supply.

Limitations:
1. Not corrosion-resistant: Anti-corrosion coating (such as galvanizing, epoxy resin) is required in humid or acidic environments.
2. Temperature sensitive: A350 LF2 should be used for extremely low temperatures (<-29°C), and A182 F11 should be used for high temperatures (>425°C).
3. Low hardness: Not suitable for high wear conditions (such as sandy media).

Common A105 flange types and application scenarios:

Welding flange (WN): high-pressure pipeline (petroleum, chemical industry)
Slip-on flange (SO): low-pressure water/air system
Blind flange (BL): pipeline plugging or system isolation
Threaded flange (THD): low-pressure, non-vibration environment (such as fire protection)

Selection considerations:

Media matching:
Corrosive media need to be replaced with stainless steel (A182 F316) or anti-corrosion coating.

Temperature limit:
When exceeding 425°C, chrome-molybdenum steel (A182 F11/F22) should be selected.

Precautions for using A105 flanges:

Although A105 flanges have many advantages, the following matters should also be noted during use:
1. Before installation, the surface of the flange should be carefully checked for defects such as cracks and sand holes to ensure its sealing and safety.
2. During the welding process, the welding temperature and time should be strictly controlled to avoid excessive thermal stress that causes flange deformation or cracking.
3. During use, the flange should be inspected and maintained regularly to ensure that it is in good working condition.
4. The bolts need to be tightened according to the "cross symmetry method" to ensure sealing.

Conclusion:

ASTM A105 pipe flange is an "economical and practical choice" for industrial pipelines. It has good mechanical properties and processing properties, and is especially suitable for normal temperature, non-corrosive, medium and high pressure conditions. However, it needs to be replaced with caution in extreme temperature or corrosive environments!

Read more: Common material types of carbon steel flanges or Pipe elbow and flange connection