When buyers choose butterfly valves, one of the first questions is: "What body material should I select?" The answer matters - because the valve body material determines strength, corrosion resistance, temperature limits, cost, and service life.
From cast iron (FC) and ductile iron (FCD, GGG40, GGG50, DI), to carbon steel (WCB, A105), stainless steel (CF8 = 304, CF8M = 316), duplex stainless steel (2520, 2507), and plastics (PVC, CPVC, PVDF) - each material has unique benefits and limitations.
Here's a clear breakdown to help you make the right choice.
Cast Iron (FC200 / GG20) – Economical, for Low-Pressure Service
Codes: JIS FC200, DIN/EN GG20 / EN-GJL-200
Features: Cost-effective and widely available, usually epoxy-coated.
Applications: Municipal water, HVAC, low-pressure pipelines.
Pros: Low cost, high hardness, easy to source.
Considerations: Limited corrosion resistance; best for non-aggressive media.
Ductile Iron (DI / FCD / GGG40 / GGG50) – Stronger, for Medium Pressure
Codes: JIS FCD450, DIN/EN GGG40 (400 MPa), GGG50 (500 MPa)
Features: Better strength and toughness than cast iron.
Applications: Wastewater treatment, medium-pressure water and gas pipelines.
Pros: Good balance of cost and strength, widely used.
Considerations: Needs protective coating; not ideal for highly corrosive conditions.
Carbon Steel (WCB / A105) – High Strength, Suitable for High-Temp/High-Pressure
Codes: Cast Steel WCB (ASTM A216, DIN 1.0619), Forged Steel A105 (DIN C22.8)
Features: Higher strength and temperature resistance than ductile iron. Performs better in certain acidic conditions (e.g., sulfuric acid) when lined.
Applications: Oil & gas, steam pipelines, power plants, heavy industry.
Pros: Strong, durable, better corrosion resistance than ductile iron.
Considerations: Prone to oxidation in humid or marine environments; protective coating recommended.
Pros: Outstanding erosion and seawater resistance.
Considerations: Higher cost; mainly used where seawater resistance is essential.
Plastics (PVC / CPVC / PVDF) – Lightweight, Chemical Resistant
Features: Lightweight and corrosion resistant, but limited in temperature/pressure.
Applications: Chemical pipelines, water treatment, laboratories.
Pros: Excellent chemical resistance, low cost, easy to install.
Considerations: Not suitable for high-pressure or high-temperature service.
| Quick Material Selection Guide
Application
Recommended Materials
Corrosion Resistance
Water & HVAC
Cast Iron, Ductile Iron
★★☆☆☆
Wastewater
Ductile Iron, Stainless Steel
★★★☆☆
Food & Beverage / Pharma
Stainless Steel (304L / 316L)
★★★★☆
Chemical Processing
Stainless Steel, PVC, CPVC, PVDF
★★★★★
High Temp / Steam
Carbon Steel, Stainless Steel, Duplex
★★★★☆
Marine / Offshore
Aluminum Bronze, Duplex Stainless Steel
★★★★★
Note: For non-corrosive marine services (e.g., freshwater, compressed air, fire protection), epoxy-coated ductile iron butterfly valves are also widely used.
Choosing the right butterfly valve body material is critical for performance and durability.
At SLVCN, with 30+ years of valve manufacturing experience, we can recommend the most suitable material based on your working conditions - and if needed, we can also customize butterfly valves in specific materials to meet your project requirements.
English
