What are the applicable media for carbon steel spiral plate heat exchangers

Source：www.cnlongyu.cn Release date： 2026-07-13

Information summary：Applicable prerequisites: medium pH=6-9, chloride ion<200mg/L, free acid, hydrogen sulfide, fluoride ion; Working temperature 0-350 ℃, pressure ≤ 2.5MPa; When the board is not lined for anti-corrosion, it is only used for non corrosive or extremely weak corrosive conditions.

Applicable prerequisites: medium pH=6-9, chloride ion<200mg/L, free acid, hydrogen sulfide, fluoride ion; Working temperature 0-350 ℃, pressure ≤ 2.5MPa; When the board is not lined for anti-corrosion, it is only used for non corrosive or extremely weak corrosive conditions.
1、 Can be used directly (carbon steel sheet without lining)
1. Water based media (most commonly used)
Circulating cooling water, softened water, boiler feedwater, desalinated water, tap water;
High temperature hot water, saturated steam, superheated steam (dry steam);
Attention: If the condensed water is acidic or contains sulfur-containing ions, carbon steel is not recommended.
2. Oil products
Crude oil, diesel, lubricating oil, engine oil, heat transfer oil, mineral oil, heavy oil, coal tar (when sulfur content is very low), ethylene glycol, propylene glycol antifreeze (neutral).
3. Gas medium (dry without water)
Dry air, nitrogen, carbon dioxide, carbon monoxide, dry coal gas, dry hydrogen gas, shift gas (excluding condensed acidic water).
4. Chemical neutral organic media
Methanol, ethanol (anhydrous), xylene, toluene, cyclohexane, alkane solvents;
Coking rich and poor oil (with very low sulfur content), rosin solution;
A weak alkaline solution of pure alkali (at room temperature, pH<9).
5. Other industrial media
Neutral saline wastewater (low chloride ion), slurry containing fine solid particles, viscous materials, and mud (non acidic).
2、 Careful selection (carbon steel is only available under specific conditions, it is recommended to prioritize carbon steel lining or replace with stainless steel)
Carbon steel can be used when the concentration of sulfuric acid is greater than 70% and the temperature is less than 65 ℃; <65% dilute sulfuric acid carbon steel is strictly prohibited from use;
Low concentration sodium carbonate solution (at room temperature) will accelerate corrosion at high temperatures;
Amine solution (MDEA): does not contain H ₂ S, cyanide ions, and can only be used at high temperatures below 104 ℃; The medium containing hydrogen sulfide is not suitable for carbon steel;
Circulating water containing a small amount of chloride ions (50-200mg/L): it is necessary to increase the corrosion allowance and control the temperature below 80 ℃; Carbon steel cannot be used with chloride ions>200mg/L.
Dilute caustic soda solution: available at room temperature and low concentration (NaOH<5%) for short-term use; High temperature concentrated alkali can cause alkali embrittlement and cracking.
3、 It is strictly prohibited to use carbon steel spiral plates (304/316L, titanium materials must be selected)
Acidic media: hydrochloric acid, hydrofluoric acid, dilute sulfuric acid, nitric acid, phosphoric acid, organic acids (acetic acid, formic acid);
Sulfur containing media: wet hydrogen sulfide, ammonium hydrosulfide, cyclic acid (high temperature);
High chlorine medium: seawater, brine, calcium chloride solution;
Concentrated alkali: High temperature NaOH and KOH solutions (prone to alkali embrittlement);
Strong oxidizing agents: hydrogen peroxide, sodium hypochlorite, ferric chloride solution;
Wet chlorine gas and wet hydrogen chloride gas; Ammonia water and ammonium solution;
Food industry edible oils, vegetable oils, dairy products (hygiene requirements, carbon steel is prone to rusting).

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