1. Material and anti-corrosion mechanism
Stainless steel pipe fittings are made of chromium-nickel alloy steel, which forms a dense oxide film on the material itself to achieve anti-corrosion. They can withstand extreme corrosive environments such as seawater, strong acids and alkalis, and do not require additional protective coatings.
Galvanized pipe fittings use carbon steel as the base material and rely on the hot-dip
galvanized layer on the surface to block corrosive media. The zinc layer is prone to red rust corrosion after wear, and the protective life is greatly affected by the construction process.
2. Physical performance comparison
Stainless Steel Pipe fittings Galvanized pipe fittings Tensile strength 520-750MPa 410-550MPa37
Ductility Can be bent by deep processing High brittleness, easy to break during processing
Surface finish Ra≤0.4μm (medical grade can reach Ra0.2μm) Zinc layer roughness Ra≥1.6μm
Temperature range -196℃~800℃ Conventional use ≤60℃
3. Economic difference
The procurement cost of galvanized pipe fittings is 30%-50% lower than that of stainless steel pipe fittings, but the following hidden costs need to be considered:
Galvanized pipes have a short maintenance cycle (replacement is required every 5-8 years), and the design life of stainless steel pipes can reach 50 years
The use of stainless steel pipes in the medical and food industries can reduce the subsequent cleaning and disinfection costs
The use of thin-walled stainless steel water supply pipes in high-rise buildings can save 18%-25% of installation space
4. Selection of applicable scenarios
Galvanized pipe fittings are preferred:
• Temporary water supply and drainage system for buildings
• Agricultural irrigation pipe network
• Low-pressure gas transmission (non-high-rise)
Required stainless steel pipe fittings:
• Offshore platforms, chemical reaction vessels
• Food and pharmaceutical sterile pipeline systems
• Precision medical equipment (such as vascular stents, dental instruments)
Neutral environment project recommendations:
New residential gas pipelines recommend 304 stainless steel bellows (lifespan > 30 years), and old residential reconstruction can use reinforced galvanized pipe fittings, which are different from
Grooved Pipe Fittings and are commonly used with stainless steel
flanges. They are commonly used in
check valves, Industrial Valves, etc.
Technical selection recommendations
A comprehensive evaluation is required when selecting: project budget (including full life cycle cost), medium corrosiveness, working pressure and temperature, and four-dimensional indicators of hygiene level requirements. Stainless steel pipe fittings have a higher overall cost-effectiveness in high-corrosion scenarios, and galvanized pipe fittings still have cost advantages in short-term projects
