{"id":3322,"date":"2026-09-02T23:11:08","date_gmt":"2026-09-02T15:11:08","guid":{"rendered":"http:\/\/www.processfolks.com\/blog\/?p=3322"},"modified":"2026-09-02T23:11:08","modified_gmt":"2026-09-02T15:11:08","slug":"what-chemicals-are-used-to-clean-heat-exchanger-tubes-4270-c2de05","status":"publish","type":"post","link":"http:\/\/www.processfolks.com\/blog\/2026\/09\/02\/what-chemicals-are-used-to-clean-heat-exchanger-tubes-4270-c2de05\/","title":{"rendered":"What chemicals are used to clean heat exchanger tubes?"},"content":{"rendered":"

As a reliable heat exchanger tube supplier, I often encounter inquiries from customers about the most effective chemicals for cleaning heat exchanger tubes. Cleaning these tubes is crucial to maintain their efficiency, extend their lifespan, and ensure the overall performance of the heat exchanger system. In this blog, I will delve into the various chemicals used for cleaning heat exchanger tubes, their applications, and the considerations for their use. Heat Exchanger Tube<\/a><\/p>\n

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Acidic Cleaners<\/h3>\n

Hydrochloric Acid (HCl)<\/h4>\n

Hydrochloric acid is one of the most commonly used acidic cleaners for heat exchanger tubes. It is highly effective in removing mineral deposits, such as calcium carbonate and magnesium hydroxide, which are often found in hard – water scale. When in contact with these deposits, hydrochloric acid reacts to form soluble salts that can be easily flushed out of the tubes.<\/p>\n

For example, the reaction with calcium carbonate is as follows:
\n[CaCO_{3}+2HCl = CaCl_{2}+H_{2}O + CO_{2}\\uparrow]<\/p>\n

However, hydrochloric acid has some drawbacks. It is a highly corrosive substance, which means it can damage the metal of the heat exchanger tubes if not used properly. Precautions must be taken to control the concentration and contact time. Industrial – grade hydrochloric acid solutions are typically used at a concentration of 10% – 20%, and the cleaning process should be closely monitored.<\/p>\n

Sulfuric Acid (H\u2082SO\u2084)<\/h4>\n

Sulfuric acid is another strong acid used for cleaning heat exchanger tubes. It is particularly useful for removing scale formed by iron oxides and some types of organic deposits. The high reactivity of sulfuric acid allows it to dissolve tough contaminants effectively.<\/p>\n

The reaction with iron oxide is:
\n[Fe_{2}O_{3}+3H_{2}SO_{4}=Fe_{2}(SO_{4}){3}+3H<\/em>{2}O]<\/p>\n

But sulfuric acid is extremely corrosive and can generate a significant amount of heat during the reaction. This heat can pose risks, including damage to the tubes and potential safety hazards for the operators. Specialized handling procedures and equipment are required when using sulfuric acid for tube cleaning.<\/p>\n

Citric Acid (C\u2086H\u2088O\u2087)<\/h4>\n

Citric acid is a milder organic acid compared to hydrochloric and sulfuric acid. It is a popular choice for cleaning heat exchanger tubes made of sensitive metals, such as copper and aluminum, because it is less corrosive. Citric acid can effectively remove light – scale deposits, such as limescale, and some organic contaminants.<\/p>\n

It has the advantage of being environmentally friendly and non – toxic. The cleaning process using citric acid is usually safer and more suitable for applications where food – grade or pharmaceutical – grade heat exchangers need to be cleaned. A typical citric acid solution for tube cleaning has a concentration of 2% – 5%.<\/p>\n

Alkaline Cleaners<\/h3>\n

Sodium Hydroxide (NaOH)<\/h4>\n

Sodium hydroxide, commonly known as caustic soda, is a powerful alkaline cleaner. It is effective in removing grease, oil, and some types of organic films from heat exchanger tubes. When sodium hydroxide reacts with fats and oils, it undergoes saponification, converting them into soluble soaps that can be washed away.<\/p>\n

The saponification reaction with a triglyceride (a common component of fats) can be represented as:
\n[C_{3}H_{5}(OOCR){3}+3NaOH = C<\/em>{3}H_{5}(OH)_{3}+3RCOONa]<\/p>\n

However, sodium hydroxide is highly caustic and can cause severe burns to skin and eyes. It also needs to be used at the appropriate concentration, usually around 1% – 5%, depending on the severity of the contamination.<\/p>\n

Potassium Hydroxide (KOH)<\/h4>\n

Potassium hydroxide is similar to sodium hydroxide in terms of its cleaning mechanism. It is also effective in removing organic contaminants, especially in applications where a more soluble alkali is required. KOH is often used in combination with other cleaning agents to enhance the cleaning effect.<\/p>\n

Potassium hydroxide solutions are generally less viscous than sodium hydroxide solutions at the same concentration, which can be an advantage in some cleaning processes. The concentration of potassium hydroxide used for heat exchanger tube cleaning typically ranges from 0.5% to 3%.<\/p>\n

Chelating Agents<\/h3>\n

Ethylenediaminetetraacetic Acid (EDTA)<\/h4>\n

EDTA is a chelating agent that forms stable complexes with metal ions. In the context of heat exchanger tube cleaning, it is used to remove metal – based deposits, such as rust and scale containing metal salts. The chelation process involves the EDTA molecule surrounding the metal ion and holding it in a soluble complex, which can then be easily removed from the tubes.<\/p>\n

EDTA is known for its selectivity in binding to specific metal ions. For example, it has a high affinity for calcium, magnesium, and iron ions. It is a relatively mild cleaning agent, making it suitable for use in heat exchangers with delicate surfaces. EDTA solutions are usually prepared at a concentration of 1% – 5%.<\/p>\n

Nitrilotriacetic Acid (NTA)<\/h4>\n

NTA is another chelating agent used for cleaning heat exchanger tubes. It has similar properties to EDTA but is more effective in certain applications, such as removing zinc – based deposits. NTA can form strong complexes with a variety of metal ions, helping to dissolve and remove scale and corrosion products from the tube surfaces.<\/p>\n

However, NTA has some environmental concerns. It can be persistent in the environment and may have some toxic effects on aquatic organisms. Therefore, its use is more restricted in some regions compared to EDTA.<\/p>\n

Surfactants<\/h3>\n

Anionic Surfactants<\/h4>\n

Anionic surfactants are commonly used in heat exchanger tube cleaning solutions. They have a negatively charged hydrophilic (water – loving) head and a hydrophobic (oil – loving) tail. This structure allows them to reduce the surface tension of water, making it easier for the cleaning solution to penetrate and wet the tube surfaces.<\/p>\n

Anionic surfactants are effective in removing oily and greasy contaminants by emulsifying them. This means that the surfactant molecules surround the oil droplets, suspending them in the water and allowing them to be flushed out of the tubes. Examples of anionic surfactants used in cleaning formulations include sodium dodecyl sulfate (SDS).<\/p>\n

Non – ionic Surfactants<\/h4>\n

Non – ionic surfactants are also widely used in heat exchanger cleaning. They do not carry an electrical charge, which makes them compatible with a wide range of other chemicals. Non – ionic surfactants are particularly useful for removing organic residues and some types of particulate matter.<\/p>\n

They can enhance the solubility of other cleaning agents and improve the overall cleaning performance. Non – ionic surfactants are often used in combination with acids, alkalis, or chelating agents to achieve better cleaning results.<\/p>\n

Considerations for Chemical Selection<\/h3>\n

When choosing the appropriate chemicals for cleaning heat exchanger tubes, several factors need to be considered:<\/p>\n