Header for Air Cooler , Carbon Steel ASME SA516 GR.60 , Plug Type
Air cooler headers can be classified into the following types:
Pipe header: It is a cylindrical header suitable for high - pressure applications (with a maximum allowable working pressure of 35 MPa). It has the characteristics of low resistance and good sealing performance, which can effectively prevent the leakage of harmful liquids and gases. It is applicable to high - temperature, high - pressure, toxic, flammable, explosive, and clean media.
Semi - circular header: This header adopts a fully welded structure without detachable parts such as wire plugs and cover plates, so it has high sealing performance. It is mainly used in the condensation of vacuum exhaust steam.
Cover plate header: It is mainly used for mixed media with a pressure of less than 6.4 MPa and is suitable for occasions that require frequent cleaning, such as very dirty flows. The cover plate can be removed for convenient cleaning.
Plug header: This is the most commonly used type of air - cooled heat exchanger structure, with an allowable working pressure of less than 20 MPa. It adopts the process of deep - hole welding and expansion, and the plugging holes are convenient for the welding, maintenance, and cleaning of the tube sheet and the base tube. It is generally used in occasions where the media side is dirty and needs frequent cleaning.
In addition, from the perspective of the inlet and outlet nozzle positions of the air cooler, it can be divided into even - pass arrangement, odd - pass arrangement, and split - header type. When the temperature difference between the inlet and outlet nozzles exceeds 111 °C, the split - header arrangement is used.
The material grades of air cooler headers can vary depending on factors such as operating pressure, temperature, corrosion resistance requirements, and cost. Here are some commonly used material grades:
Carbon Steel
A36: It has relatively low strength and is easy to process and weld. It is suitable for air coolers in some non - corrosive environments with low - pressure and low - temperature operating conditions, such as general - purpose industrial air coolers.
A106 Grade B: This material has good mechanical properties and can withstand higher pressures. It is often used in air cooler headers in petroleum, chemical, and other industries, especially in applications where the medium is non - corrosive or has low - corrosion requirements.
Stainless Steel
304 Stainless Steel: It has excellent corrosion resistance, good formability, and weldability. It is suitable for air coolers in environments with mild corrosive media, such as those in the food, beverage, and some chemical industries. It can also resist atmospheric corrosion and certain acid - base solutions.
316 Stainless Steel: It has better corrosion resistance than 304 stainless steel, especially in chloride - containing environments. It is often used in air coolers in marine - related industries, offshore platforms, and some chemical process applications where higher corrosion resistance is required.
Alloy Steel
Alloy 825: It has high corrosion resistance and can resist the corrosion of various acids, alkalis, and salts. It is widely used in air coolers in the petroleum, chemical, and other industries, especially in some high - temperature and high - pressure environments with corrosive media.
Duplex Stainless Steel: It has a two - phase structure of ferrite and austenite, which combines the advantages of both, such as high strength, good corrosion resistance, and stress - corrosion cracking resistance. It is suitable for air coolers in harsh environments, such as those in the chemical, marine, and oil and gas industries.