SJ Gauge: Pressure gauges or diaphragm pressure gauges, due to their measurement principles, have connectors that come into contact with the pressure source (medium). For fluids with corrosive properties, we often choose pressure gauges with plastic connectors or diaphragms. The following is a list of common plastic materials used in pressure gauges and their corrosion resistance to different pressure sources (information is for reference only, and actual conditions may vary; rely on on-site experience for accurate assessment):
 

Corrosion Resistance Table for Common Pressure Gauge Plastic Materials

Symbol Explanation:
✓: Highly resistant, ○: Suitable X: Not recommended
⊗: Partially suitable (e.g., at high concentrations or in the presence of moisture).
      PP PVC PVDF PTFE PFA
  Water H2O ✓ ✓ ✓ ✓ ✓
Hydrogen H2 ✓ ✓ ✓ ✓ ✓
Nitric Oxide N2O ✓ ✓ ✓ ✓ ✓
Hydrogen Peroxide H2O2 ○ ✓ ○ ✓ ✓
Acid Hydrochloric Acid HCl ✓ ✓ ✓ ✓ ✓
Nitric Acid HNO3 ○ ✓ ✓ ✓ ✓
Sulfuric Acid H2SO4 ○ ✓ ✓ ✓ ✓
Hydrogen Sulfide H2S ✓ ✓ ✓ ✓ ✓
Carbonate H2CO3 ✓ ✓ ✓ ✓ ✓
Phosphoric Acid H3PO4 ✓ ✓ ✓ ✓ ✓
Chromic Acid H2CrO4 ○ ✓ ○ ✓ ✓
Hydrofluoric Acid HF ○ ○ ✓ ✓ ✓
Chloric Acid HClO3 ○ ✓ ✓ ✓ ✓
Sulfur Dioxide SO2 ✓ ✓ ✓ ✓ ✓
Alkali Sodium Hydroxide NaOH ✓ ✓ ✓ ✓ ✓
Ammonia NH3 - - - ✓ ✓
Salt Salt    Ammonium Nitrate NH4NO3 ✓ - ✓ ✓ ✓
Ammonium Sulfate (NH4)2SO4 ✓ ✓ ✓ ✓ ✓
Ammonium Sulfate Al2 (SO4)3 ✓ ✓ ✓ ✓ ✓
Sulfates    Sulfate Sulfate ✓ ✓ ✓ ✓ ✓
Ammonium Bicarbonate NH4HCO3 ✓ ✓ ✓ ✓ ✓
Sodium Carbonate Na2CO3 ✓ ✓ ✓ ✓ ✓
Sodium Bicarbonate NaHCO3 ○ ✓ ✓ ✓ ✓
Ammonium Chloride NH4CI ✓ ✓ ✓ ✓ ✓
Potassium Chloride KCI ✓ ✓ ✓ ✓ ✓
Iron Chloride    FeCl3 FeCl3 ✓ ✓ ✓ ✓ ✓
Sodium Hypochlorite NaOCl ○ ✓ ✓ ✓ ✓
Aqueous Mineral water ✓ ✓ ✓ ✓ ✓
Sewage ✓ ✓ ✓ ✓ ✓
Brines ✓ ✓ ✓ ✓ ✓
30% NaCl ✓ ✓ ✓ ✓ ✓
Beer ✓ ✓ ✓ ✓ ✓
Juice ✓ ✓ ✓ ✓ ✓
Toxicity Sulfur Sulfur - - - ✓ ✓
Chlorine Gas Cl2 ✓ ✓ ✓ ✓ ✓
Chlorine Water Chlorinated Water ✓ ✓ ✓ ✓ ✓
Bromine Gas Br2 X X ⊗ ✓ ✓
Phosgene COCI2 ✓ ✓ ✓ ✓ ✓
Organic Organic    Acetic Acid CH3COOH ✓ ✓ ✓ ✓ ✓
Ammonium Acetate CH3COONH4 ✓ - - ✓ ✓
Glycerol Glycerol ✓ ✓ ✓ ✓ ✓
Xylene C8H10 X X ○ ✓ ✓
Methanol CH3OH ○ ✓ ✓ ✓ ✓
Ethanol C2H5OH ○ ✓ ✓ ✓ ✓
Methane CH4 ✓ ✓ ✓ ✓ ✓
Dichloroethylene C2H4CI2 X X ✓ ✓ ✓
Chloroform CHCI3 X X ✓ ✓ ✓
Vinyl Chloride C2HCI3 X X ✓ ✓ ✓
Cellulose Acetate cellulose acetate - - - ✓ ✓
Citric Acid C6H8O7 ○ ⊗ ✓ ✓ ✓
Crude Oil Crude ✓ ✓ ✓ ✓ ✓
Freon Freon ✓ ✓ ✓ ✓ ✓


SJ Gauge®SJ®Technical Research Department

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