Hygienic stainless steel pipework is a specialized system designed to prevent contamination in sensitive processes by using materials with smooth, non-porous surfaces that inhibit bacterial growth. It is primarily used in industries such as food and beverage, pharmaceutical, and biotechnology.
Key Properties & Standards
Hygienic pipework is designed to be crevice-free to ensure easy and effective cleaning through Clean-In-Place (CIP) or Sterilize-In-Place (SIP) systems.
- Materials: The most common grades used are AISI 304L and AISI 316L stainless steel. 316L offers superior corrosion resistance, especially in chloride-rich or highly acidic environments due to the addition of molybdenum.
- Surface Finish: The internal surface is crucial and is often dull or bright polished to a specific roughness average (Ra) to minimize microbial adhesion. Internal weld beads are typically removed or rolled flat to eliminate crevices.
- Standards: Key international standards for hygienic pipework include EN 10357 (formerly DIN 11850), BS 4825 Part 1, ISO 2037, and ASTM A270.
- Connection Types:
- Orbital Welding: Provides a permanent, smooth, crevice-free connection that is ideal for high-purity systems.
- Tri-Clamp (Tri-Clover): A popular connection using ferrules, a gasket, and a clamp, which is easy to assemble, disassemble, and clean, making it perfect for lines requiring frequent manual cleaning.
- RJT, IDF, DIN, and SMS variants: Other specific union types are also used, offering different levels of hygiene and ease of use.
