Selection guide for stainless steel valves under different corrosion conditions

Today, I have sorted out the selection guide of stainless steel valves in different corrosion conditions, to help you figure out what can be used and what can not be used.

1. Water conditions: ordinary normal temperature water, 201, 304, 316 can be used, 201 is the cheapest, but can only be used in clean water, 304 is the highest cost performance ratio, most of the water conditions can be used, 316 is suitable for higher requirements.

2. Seawater condition: 304 can not be used, chloride ions in seawater will corrode 304, resulting in pitting corrosion, and it will not take long for rust to leak. 316 room temperature clean seawater can make do, but if the temperature is high, or there is polluted seawater, it is necessary to use dual-phase steel, or fluorine lining.

3. Liquid ammonia conditions: stainless steel can not be used, liquid ammonia and stainless steel stress corrosion, resulting in stainless steel cracking, many customers use stainless steel, with not long to crack, leakage ammonia, very dangerous, liquid ammonia conditions, to use carbon steel, or Monel.

4. Hydrogen peroxide working condition: low concentration of 3% of medical hydrogen peroxide, 304 can make do, but high concentration of industrial grade, 27.5%, 50%, stainless steel can not be used, will catalyze the decomposition of hydrogen peroxide, produce a lot of oxygen, pressure suddenly increased, even explosion, to use fluorine.

5. Sodium hypochlorite working conditions: stainless steel can not be used, sodium hypochlorite is a strong oxidant, will corrode stainless steel, it will not take long to rust leakage, to use fluorine lined, many customers bought stainless steel, with not long to leak, rework spent a lot of money.

6. Hydrochloric acid working condition: stainless steel can not be used, hydrochloric acid will corrode stainless steel very fast, with less than a month to leak, to use fluorine lining, or Hastelloy alloy.

7. Caustic soda working conditions: normal temperature and low concentration, 304 can make do, but high temperature and high concentration, stainless steel will occur alkali brittle, cracking, to use Monel.