304/316 Stainless Steel Pipe - OD 6-300mm, WT 0.8-12mm, Seamless/Welded, Corrosion Resistant for Food Industry, Chemical Engineering & Water Treatment

Versatile corrosion resistance: Resists erosion from air, water, and weak acids/alkalis (e.g., food-grade citric acid).

Cost-effectiveness: Lower cost than 316, suitable for general industrial scenarios.

Composition: Contains 18% chromium (Cr), 8% nickel (Ni), and no molybdenum (Mo).

Advantages:

Typical Applications: Food processing equipment, drinking water pipelines, general chemical piping.

Chloride environment resistance: Performs excellently in chloride-ion (Cl?) environments (e.g., seawater, brine, chemical wastewater).

High-temperature stability: Withstands extreme temperatures from -200°C to 800°C.

Composition: Contains 2-3% molybdenum (Mo), significantly enhancing pitting corrosion resistance.

Advantages:

Typical Applications: Marine engineering, pharmaceutical equipment, high-concentration acid/alkali transfer pipelines.

High strength: Tensile strength ≥ 520MPa (ASTM A213), suitable for high-pressure steam pipelines.

Uniformity: No weld defects, ideal for extreme safety scenarios like nuclear industry.

Piercing and rolling: Solid round billets heated to 1200°C, pierced and rolled into hollow shells.

Cold drawing finishing: Stretched via multi-stage dies, with tolerance controlled to ±0.5% of OD.

Cost efficiency: 15-20% cheaper than seamless pipes, ideal for large-scale water supply and drainage projects.

Custom flexibility: Produce non-standard sizes (e.g., elliptical, square/rectangular pipes).

Electric Resistance Welding (ERW): Coiled plates formed, then welded via high-frequency current, with speeds of 6-10m/min.

Laser welding: Weld width ≤ 0.3mm, suitable for ultra-thin walls (WT ≤ 1.5mm).

304 stainless steel: No red rust after 72 hours in 5% NaCl solution (rating ≥ 9).

316 stainless steel: Passes 1000-hour salt spray test with only minor surface discoloration (rating ≥ 8).

304L (low-carbon): Corrosion rate ≤ 0.02mm/year after sensitization.

316L (ultra-low carbon): Corrosion rate ≤ 0.01mm/year in boiling 65% nitric acid.

Food Industry: A dairy plant used 304 stainless steel pipes for pasteurized milk transfer; no rust after 10 years, with colony counts <10CFU/cm2.

Chemical Industry: A chemical plant used 316 stainless steel pipes for 30% hydrochloric acid transfer; wall thickness loss <0.5mm after 8 years (design lifespan 10 years).

ASTM A249 (welded pipes): Requires ≥ 98% pass rate for radiographic testing (RT) of welds.

EN 10216-5 (seamless pipes): Mandates 100% ultrasonic testing (UT) per pipe, with defect equivalent ≤ φ2mm.

ASME B36.19M: Specifies OD tolerance (±1%) and WT tolerance (±10%).

Food-Grade: Compliant with NSF/ANSI 61 (drinking water contact components) and 3A Sanitary Standards (dairy equipment).

Chemical: Meets ASME BPVC Section VIII (pressure vessel code) and offers PED 2014/68/EU certification.