Performance index of flange

Performance index of flange

Flange material

Flanges are generally made of cast iron, steel, stainless steel, copper, aluminum, etc. Special materials can also be customized according to usage requirements. Flanges made of different materials have different properties such as corrosion resistance, temperature range, strength and deformation rate.

1. Carbon steel flange

Carbon steel flange is a commonly used flange, usually suitable for low pressure and low temperature conditions. It is mainly made of carbon steel, which has the characteristics of light weight, high strength and low price.

2. Stainless steel flange

Stainless steel flanges are mainly made of stainless steel and have strong corrosion resistance. They are widely used in food, medicine, petroleum, chemical and other industries. They have excellent high temperature resistance, low temperature resistance, corrosion resistance and resistance to oxidation.

3.Alloy steel flange

Alloy steel flanges are made of alloy steel and have superior strength and wear resistance. They are often used for pipe connections under harsh conditions such as high pressure, high temperature, and strong corrosion.

4.Cast iron flange

Cast iron flanges are mainly made of gray cast iron, ductile iron, cast iron and other materials. They have the advantages of high strength, good reliability and low cost.

5.Plastic flange

Plastic flanges are mainly made of PVC, PP, PE, PVDF and other materials. They are corrosion-resistant, transparent, flame-retardant, sound-insulating and other properties. They are a type of connector widely used in chemical industry, tap water, sewage treatment and other industries.

Gasket type

Commonly used gasket types include soft iron gaskets, ferrocyanate-coated gaskets, asbestos rubber gaskets, etc. Different types of gaskets have different sealing properties and pressure resistance capabilities.

1. Rubber gasket

Rubber gasket is the most common flange sealing gasket. It is made of rubber material and has good sealing and corrosion resistance. Commonly used materials include nitrile rubber, neoprene rubber, silicone rubber and fluorine rubber. Its characteristics are oil resistance, water resistance, acid and alkali resistance, heat resistance, cold resistance, wear resistance, and high tensile strength. Due to their good sealing properties, rubber gaskets are widely used in chemical, petroleum, food, pharmaceutical and other industries.

2. Fiber gasket

Fiber gaskets are made of natural fibers or chemical fibers and usually need to be coated with an anti-corrosion layer or rubber to improve their sealing and corrosion resistance. Commonly used materials include asbestos, asbestos-free, blue asbestos, black asbestos, mica, etc. Because fiber gaskets are environmentally friendly, safe and cheap, they are widely used in construction, water treatment, sewage and other industries.

3. Metal gasket

Metal gaskets are made of stainless steel, copper, aluminum and other metal materials. They have good high temperature pressure resistance and wear resistance and are widely used in high temperature, high pressure and closed systems. Metal gaskets can resist acid and alkali corrosion, maintain stable performance, and have a long service life. It is widely used in the fields of chemical industry, petroleum, natural gas, automobile and aviation.

4. Bellows type gasket

Bellows-type gaskets are gaskets composed of metal or rubber bellows and support rings. The deformation of the bellows will generate compressive force, making it have good sealing and elasticity. Bellows gaskets have waterproof, shockproof, sound insulation and heat resistance properties and are widely used in conveying machinery, pipeline and container sealing and other fields.

Sealing of flange

The sealing performance of a flange refers to its sealing ability under working pressure. Commonly used flange sealing levels include PN6, PN10, PN16, PN25, PN40, etc. Generally, appropriate flange sealing should be selected based on working conditions such as medium, pressure, temperature, etc.

1.Gasket seal

Gasket sealing is the most commonly used sealing method in flange connections. Gaskets are usually made of rubber, plastic, copper, iron sheets and other materials. Their function is to fill the gaps between flanges and prevent fluid leakage. The gasket can withstand a certain pressure, adapt to temperature changes, and ensure the sealing of the connection.

2. Metal gasket seal

Metal gasket seals are similar to gasket seals, except that the gasket is made of metal material. The sealing performance of metal gasket seals is better than that of ordinary gasket seals, and it can withstand applications in high temperature and high pressure environments. Metal gaskets are usually made of stainless steel or copper, and their manufacturing process is complex and the cost is relatively high.

3. Bellows seal

Bellows seal is a sealing method consisting of bellows and flange. Corrugated pipe is a shaped pipe made of stainless steel or copper, which is characterized by its ability to bend freely and excellent sealing performance. Bellows seals have good corrosion resistance and durability in high temperature and high pressure environments, and are widely used in chemical, petroleum, natural gas and other industries.

Carrying capacity

The load-bearing capacity refers to the load-bearing capacity of the flange under pressure. Generally expressed by PN value, the higher the PN value, the stronger the carrying capacity. The flange pressure rating refers to the sealing capacity of the flange-connected container, which ranges from zero to infinity. According to common domestic and foreign standards, flange pressure levels are divided into PN10, PN16, PN25, PN40, PN63, PN100 and ANSI 150, ANSI 300, ANSI 600 levels. Among them, "PN" refers to the standard internal pressure in bar, which indicates the maximum load-bearing capacity of the flange connection in a leak-free state, while "ANSI" refers to the pressure level using the American Standards Institute (ANSI).

Commonly used pressure levels and corresponding load-bearing capacities

1. PN10 level: The carrying capacity is 10 bar, usually used for the connection of low-pressure vessels, such as water supply and drainage pipes, sprinkler irrigation systems, etc.;

2. PN16 level: The carrying capacity is 16 bar, suitable for conventional industrial systems, such as pipelines, chemical equipment, etc.;

3. PN25 grade: The carrying capacity is 25 bar, suitable for the connection of high-pressure vessels, such as petrochemical, aerospace and other fields;

4. PN40 grade: carrying capacity is 40 bar, used for high-strength, high-sealing container connections, such as nuclear industry, heavy machinery, etc.;

5. ANSI 150 grade: carrying capacity is 150 pounds per square inch, commonly used in low-pressure piping systems;

6. ANSI 300 grade: The load-bearing capacity is 300 pounds per square inch, suitable for medium pressure systems, and can withstand certain temperatures and corrosive media;

7. ANSI 600 rating: Load capacity is 600 pounds per square inch, typically used in high pressure and high temperature systems.

Choose the right flange

Choosing a suitable flange needs to be determined based on the specific use environment and requirements. It is recommended to consider factors such as application environment, pressure, temperature, medium, etc. before selection, and Then select the appropriate flange material, gasket type, sealing, load-bearing capacity and other parameters according to your needs from a qualified flange supplier.

Other things to note

When installing flanges, you need to install them according to the installation drawings and appropriate tools, and follow the correct installation steps and principles. During use, you also need to pay attention to regular maintenance of the flange to ensure its normal operation.

In short, a correct understanding and selection of the appropriate flange can ensure a safe and reliable working environment, improve its performance and service life, and reduce the number of maintenance and replacements.