Plate material for plate heat exchangers

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The plates of a plate heat exchanger are stamped in one go using highly precise molds; plates from the same batch have the same level of precision, and there are uniform metal contact points between the plates. This ensures that the plate heat exchanger can operate under normal working pressures and withstand certain pressure shocks. In plate heat exchangers, different heat exchange media can be corrosive to the corresponding material plates; therefore, it is very important to select an appropriate material for the plate heat exchanger based on the type of heat exchange medium used. Below, the editor provides a detailed introduction to the materials used for the plates in plate heat exchangers: 1. Stainless steels such as 304, 316, and 316L: Plates made of stainless steel exhibit good corrosion resistance and offer a good cost-performance ratio; they are suitable for heat exchange media with low chloride content, such as purified water, river water, edible oil, and mineral oil. Most plate heat exchanger plates are made of stainless steel. 2. Titanium plates: Plate heat exchangers use unalloyed titanium, which is lightweight and of high quality. It can naturally form a passivation layer that repairs itself when damaged; as a result, it has better corrosion resistance than stainless steel. Although its price is higher, it is suitable for heat exchange media containing high levels of chloride ions, such as seawater, brine, and salts. 3. Titanium-palladium alloy: Plate heat exchangers use unalloyed titanium to which palladium (0.12%~0.25%) has been added, which improves the corrosion resistance of titanium in acidic liquids; it is suitable for use in media such as hydrochloric acid, nitric acid, and sulfuric acid, under certain specific operating conditions. 4. SMO254: An austenitic stainless steel that, due to its high molybdenum content, exhibits excellent resistance to chloride pitting and crevice corrosion. It is suitable for use in media such as dilute sulfuric acid, dilute saline solutions, and inorganic aqueous solutions where 316 type stainless steel cannot be used. It is a cost-effective stainless steel widely employed in industries such as chemicals and desulfurization and environmental protection. 5. Nickel: This is pure nickel plate with a nickel content of over 99%. It is mainly used in highly concentrated, high-temperature caustic alkali solutions (such as NaOH, KOH, etc.), and exhibits good corrosion resistance in alkaline and neutral solution media containing salts such as carbonates, nitrates, oxides, and acetates. However, it is highly sensitive to crevice corrosion caused by chlorides such as brackish water.