Technical Reference

Valve Selection by Fluid Service

Material compatibility tables and valve selection guides for 54 industrial fluids — from corrosive acids to cryogenic LNG to high-pressure hydrogen.

Corrosive Fluids

Sulphuric Acid (H₂SO₄)

H₂SO₄

Sulphuric acid is one of the most widely used industrial chemicals.

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Hydrochloric Acid (HCl)

HCl

Hydrochloric acid is extremely aggressive to most metals.

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Seawater

Seawater is highly corrosive due to dissolved chlorides (~3.

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Caustic Soda (NaOH)

NaOH

Sodium hydroxide (caustic soda) is used extensively in the chlor-alkali industry, paper & pulp, alumina refining, and chemical manufacturing.

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Phosphoric Acid (H₃PO₄)

H₃PO₄

Phosphoric acid is a moderate acid used in fertiliser production (wet process phosphoric acid), food processing, metal surface treatment, and semiconductor manufacturing.

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Nitric Acid (HNO₃)

HNO₃

Nitric acid is a strong oxidising acid used in fertiliser production, explosives manufacturing, stainless steel passivation, and pharmaceutical synthesis.

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Brine / Sodium Chloride Solution

Brine (sodium chloride solution) is handled in chlor-alkali production, food processing, desalination, and produced water from oil wells.

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Amine (DEA / MEA / MDEA - Gas Sweetening)

Amine solutions - diethanolamine (DEA), monoethanolamine (MEA), and methyldiethanolamine (MDEA) - are used extensively in natural gas and refinery gas sweetening units to remove hydrogen sulphide (H₂S) and carbon dioxide (CO₂) from sour gas streams.

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Urea Solution (Carbamide / DEF / AdBlue)

CO(NH₂)₂

Urea solution is encountered in three main industrial contexts: (1) 32.

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Acetic Acid (CH₃COOH)

CH₃COOH

Acetic acid is a key industrial chemical used as a solvent and as feedstock for PTA (purified terephthalic acid), vinyl acetate monomer, cellulose acetate, and acetic anhydride.

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Phenol (C₆H₅OH - Carbolic Acid)

C₆H₅OH

Phenol (carbolic acid) is an aromatic compound that is solid at ambient temperature (melting point 41°C) but handled as a liquid by heat tracing pipelines at 50–80°C.

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Sodium Hypochlorite (NaOCl - Bleach)

NaOCl

Sodium hypochlorite (NaOCl) is used as a disinfectant and bleaching agent in water treatment (typically 0.

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Caustic Potash (KOH - Potassium Hydroxide)

KOH

Potassium hydroxide (caustic potash, KOH) is a strong alkaline chemical used in potassium soap production, fertilisers, batteries (alkaline and nickel metal hydride), electrolysers for green hydrogen production, and as a pH adjuster.

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Hazardous / Toxic

Chlorine (Cl₂)

Cl₂

Chlorine is a powerful oxidiser and highly toxic gas (IDLH: 10 ppm).

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Ammonia (NH₃)

NH₃

Ammonia is handled as a refrigerant (R-717), in fertiliser production, and as a chemical feedstock.

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Hydrogen (H₂)

H₂

Hydrogen is the smallest molecule - extreme permeation tendency, wide flammability range (4–75%), and susceptibility to hydrogen embrittlement in high-strength steels.

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Hydrofluoric Acid (HF)

HF

Hydrofluoric acid is one of the most hazardous industrial chemicals.

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Oxygen (O₂ - Industrial and Medical Grade)

O₂

Oxygen in industrial concentrations (>23.

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Synthesis Gas (Syngas - CO + H₂)

CO + H₂

Synthesis gas (syngas) is a mixture of carbon monoxide (CO) and hydrogen (H₂) produced by steam methane reforming (SMR), partial oxidation, or gasification of coal, biomass, or refinery residues.

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Chlorine Dioxide (ClO₂)

ClO₂

Chlorine dioxide is a powerful oxidising biocide used in pulp and paper bleaching (replacing elemental chlorine), municipal drinking water treatment, and food plant sanitisation.

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Hydrogen Sulphide (H₂S - Sour Gas)

H₂S

Hydrogen sulphide (H₂S) is a highly toxic, flammable gas encountered in crude oil and natural gas production ('sour service'), refinery amine treating, geothermal wells, biogas/landfill gas, and Claus sulphur recovery units.

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Carbon Monoxide (CO)

CO

Carbon monoxide is a colourless, odourless, highly toxic gas encountered in syngas (CO + H₂), steel plant blast furnace gas (BFG), coke oven gas (COG), methanol synthesis, Oxo alcohols production, and as a combustion product.

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Hydrocarbons

Crude Oil

Crude oil is a complex mixture of hydrocarbons, water, gases (including H₂S), sediment, and wax.

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LPG - Liquefied Petroleum Gas

LPG (propane/butane mixture) is stored and transported as a pressurised liquid.

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Natural Gas

Natural gas (primarily methane) is transported in high-pressure pipelines and distributed at lower pressures.

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Diesel Fuel / Fuel Oil

Diesel and fuel oil (HSD, LDO, HFO) are widely used petroleum products handled in refineries, terminals, power plants, and marine vessels.

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Acetone (Propanone)

C₃H₆O

Acetone is a highly flammable solvent used in pharmaceuticals, cosmetics, adhesives, and chemical synthesis.

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Methanol (Methyl Alcohol)

CH₃OH

Methanol is a highly flammable, toxic alcohol used as a fuel additive (MTBE/FAME production), chemical feedstock, and hydrate inhibitor in gas pipelines.

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Hot Oil (Thermal Heat Transfer Fluid)

Hot oil or thermal fluid is used as a heat transfer medium in indirect heating systems - circulated through heaters and heat exchangers to transfer heat without generating steam.

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Ethylene (C₂H₄)

C₂H₄

Ethylene is the world's largest-volume petrochemical feedstock - produced by steam cracking of naphtha, ethane, or LPG, then used to manufacture polyethylene, PVC, ethylene oxide, styrene, and dozens of downstream chemicals.

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Ethanol / Industrial Alcohol (C₂H₅OH)

C₂H₅OH

Industrial ethanol encompasses fuel ethanol from sugar/grain fermentation, pharmaceutical-grade ethanol (IPA equivalent), and solvent ethanol used in chemical synthesis.

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Propylene / Propene (C₃H₆)

C₃H₆

Propylene is a key olefin feedstock produced by steam cracking and FCC units, used to make polypropylene (PP), acrylonitrile, propylene oxide, and cumene.

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Xylene (C₈H₁₀ - Ortho, Meta, Para)

C₈H₁₀

Xylenes are aromatic hydrocarbons produced from catalytic reforming and coal tar distillation, widely used as solvents and as feedstocks for PTA (purified terephthalic acid, the monomer for PET polyester).

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Toluene (C₇H₈)

C₇H₈

Toluene is an aromatic hydrocarbon solvent used in paints, adhesives, pharmaceuticals, and as a gasoline blending component.

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Heavy Fuel Oil (HFO / Bunker C / Fuel Oil No. 6)

Complex hydrocarbons (C₂₀–C₅₀)

Heavy fuel oil (HFO), also known as bunker fuel, residual fuel oil, or Fuel Oil No.

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Naphtha (Light / Heavy Naphtha)

C₅–C₁₂ hydrocarbons

Naphtha is a broad distillate fraction of crude oil (boiling range ~30–200°C) used as gasoline blending stock, as feedstock for catalytic reforming (to make BTX aromatics), as petrochemical cracker feed, and as a solvent.

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Propane (C₃H₈ - LPG Component)

C₃H₈

Propane is a liquefied petroleum gas (LPG) component used for domestic and industrial heating, as an industrial fuel, as a petrochemical feedstock (propane dehydrogenation to propylene), and as an aerosol propellant.

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Utility Fluids

High-Pressure Steam

Steam is the most common industrial utility fluid.

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Carbon Dioxide (CO₂)

CO₂

CO₂ is used in supercritical extraction, fire suppression, EOR (Enhanced Oil Recovery), CCS (Carbon Capture Storage), and beverage carbonation.

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Cooling Water

Cooling water - open or closed circuit - is found in almost every industrial plant.

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Compressed Air

N₂ / O₂ mixture

Compressed air is the most widely used utility in industrial plants - powering pneumatic actuators, instruments, tools, conveying systems, and process air injection.

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MEG / Glycol (Monoethylene Glycol - Gas Dehydration)

C₂H₆O₂

Monoethylene glycol (MEG) is used as a hydrate inhibitor in natural gas pipelines and as a refrigerant in gas processing plants.

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Demineralised Water (DM Water / Deionised Water)

Demineralised water (DM water) is ultra-pure water with almost all dissolved minerals removed by ion exchange or reverse osmosis.

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Nitrogen (N₂)

N₂

Nitrogen is an inert utility gas used throughout industry for blanketing, purging, pressurisation, and inerting of vessels, pipelines, and tanks.

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Argon (Ar)

Ar

Argon is a chemically inert noble gas used extensively in steel manufacturing (EAF and BOF purging, ladle rinsing), welding (shielding gas), semiconductor fab, and as a product of air separation units.

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Boiler Feedwater (BFW)

H₂O (treated)

Boiler feedwater is highly purified, deaerated, and chemically dosed water supplied to steam boilers at pressure and elevated temperature.

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Glycerine / Glycerol (C₃H₈O₃)

C₃H₈O₃

Glycerine (glycerol) is a colourless, viscous, water-miscible alcohol with diverse industrial applications including pharmaceuticals, food, cosmetics, and as a by-product of biodiesel production (transesterification).

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Hot Water (District Heating / Process Hot Water)

H₂O (pressurised)

Hot water service covers a wide range of applications from domestic heating circuits (60–90°C, 6–10 barg) to district heating networks (130–180°C, 10–25 barg) and process hot oil equivalent water circuits.

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Vacuum Service

Sub-atmospheric pressure

Vacuum service encompasses any application where the process pressure is below atmospheric (0.

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Engineering Disclaimer

All fluid compatibility information on this site is indicative only, based on published corrosion engineering data. Actual material suitability depends on concentration, temperature, flow velocity, pH, dissolved gases, and presence of contaminants. All specifications must be reviewed by a qualified materials or process engineer before procurement. Vajra Industrial Solutions and VajraVyuh Enterprise Pvt. Ltd. accept no liability for any consequence of specifications made based on this reference material.