Valve Material Selection Guide
Choosing the right material is critical for valve performance, safety, and lifecycle cost. This guide covers all common valve body, trim, and seat materials with temperature limits, corrosion resistance, and application guidance.
Quick Material Selection Rule
Water/Steam/Oil (standard): Carbon Steel (WCB). High-temp steam (>425°C): Alloy Steel (WC6/WC9). Corrosive/Chemical: SS316 (CF8M). Seawater/Marine: NAB (C95800) or Super Duplex. Chloride/Offshore: Duplex/Super Duplex. Aggressive acids: Hastelloy C276. Cryogenic (LNG): SS304 (CF8) or LF2. Low-pressure water/plumbing: Bronze (LTB2) or Cast Iron.
Valve Body Material Comparison
| Material | ASTM Spec | Grade | Temp Range | Best For | Cost |
|---|---|---|---|---|---|
| Carbon Steel | A216 (cast) / A105 (forged) | WCB / A105 | -29 to +425°C | Water, steam, oil, gas – general service | $ |
| Low-Temp Carbon Steel | A352 (cast) / A350 (forged) | LCB / LF2 | -46 to +340°C | Low-temperature, cryogenic down to -46°C | $$ |
| Alloy Steel (1.25Cr) | A217 (cast) / A182 (forged) | WC6 / F11 | -29 to +538°C | High-temp steam, power plants | $$ |
| Alloy Steel (2.25Cr) | A217 / A182 | WC9 / F22 | -29 to +593°C | High-temp steam, refinery, power | $$ |
| Alloy Steel (5Cr) | A217 / A182 | C5 / F5 | -29 to +649°C | Very high-temp, sulfur-bearing crude | $$$ |
| SS 304 | A351 (cast) / A182 (forged) | CF8 / F304 | -196 to +425°C | Mild corrosive, cryogenic, food grade | $$$ |
| SS 316 | A351 / A182 | CF8M / F316 | -196 to +425°C | Corrosive, chloride, seawater, pharma | $$$ |
| SS 316L | A351 / A182 | CF3M / F316L | -196 to +425°C | Welded service, intergranular corrosion | $$$ |
| Duplex 2205 | A890 (cast) / A182 (forged) | 4A / F51 | -46 to +315°C | Offshore, chloride, desalination | $$$$ |
| Super Duplex 2507 | A890 / A182 | 5A / F53 | -46 to +315°C | Aggressive seawater, subsea, hot chloride | $$$$$ |
| NAB (Ni-Al Bronze) | B148 | C95800 | -196 to +260°C | Marine, seawater, shipboard, offshore | $$$$ |
| Monel 400 | A494 | M35-1 | -196 to +480°C | Hydrofluoric acid, seawater, alkalis | $$$$$ |
| Hastelloy C276 | A494 | CW-12MW | -196 to +425°C | Strong acids, chlorine, wet flue gas | $$$$$$ |
| Inconel 625 | A494 | CY-40 | -196 to +650°C | High-temp corrosion, nuclear, aerospace | $$$$$$ |
| Bronze | IS 318 | LTB2 | -20 to +225°C | Water, oil, plumbing, marine (small bore) | $$ |
| Cast Iron | IS 210 / ASTM A126 | FG 200/260 | -10 to +200°C | Water, sewage, low-pressure gas | $ |
| Ductile Iron | IS 1865 / ASTM A536 | GGG40/50 | -20 to +350°C | Water, wastewater, fire protection | $ |
Seat & Seal Material Guide
| Material | Temp Range | Best For | Limitations |
|---|---|---|---|
| PTFE (Teflon) | -200 to +260°C | Chemicals, acids, solvents, food. Universal chemical resistance. | Cold flow under load, not for high pressure |
| RPTFE (Reinforced PTFE) | -200 to +260°C | Higher pressure than virgin PTFE, better dimensional stability | Slightly less chemical resistance than virgin PTFE |
| EPDM | -40 to +120°C | Water, wastewater, steam (low temp), mild chemicals | Not for oil/hydrocarbon service |
| NBR (Nitrile/Buna-N) | -30 to +100°C | Oil, fuel, hydraulic fluid, petroleum products | Not for ketones, strong acids, ozone |
| Viton (FKM) | -20 to +200°C | High-temp chemicals, fuels, acids, solvents | Not for ketones, amines, hot water |
| Metal (Stellite 6) | -196 to +816°C | High-temp, high-pressure, erosive service, fire-safe | Higher torque, not bubble-tight at low pressure |
| Graphite | -200 to +650°C | High-temp steam, fire-safe, nuclear | Oxidizes above 450°C in air |
| PEEK | -60 to +250°C | Aggressive chemicals, high pressure, abrasive | Expensive |
Corrosion Resistance Chart
| Media | WCB | SS304 | SS316 | Duplex | NAB | Hastelloy | Monel |
|---|---|---|---|---|---|---|---|
| Fresh Water | A | A | A | A | A | A | A |
| Seawater | D | C | B | A | A | A | A |
| Sulfuric Acid (dilute) | D | C | B | B | C | A | B |
| Hydrochloric Acid | D | D | D | C | D | A | B |
| Hydrofluoric Acid | D | D | D | D | D | B | A |
| Caustic Soda (NaOH) | B | A | A | B | B | A | A |
| Chloride (>50 ppm) | A | D | C | A | A | A | A |
| Steam (standard) | A | A | A | B | B | A | A |
| H₂S (Sour Service) | B* | B | B | A | C | A | C |
A = Excellent, B = Good, C = Fair (limited use), D = Not recommended. *WCB for sour service must comply with NACE MR0175.
Need Material Selection Assistance?
Our technical team can help select the right material for your specific media, temperature, and pressure conditions. We supply valves in all materials listed above.