Saunders®: Surface Finish For Life Science Industries With 316L Stainless Steel.pdf

Key points include:

- Material: 316L (DIN 1.4435) Stainless Steel is the primary material, known for its strength, corrosion resistance, compatibility with high purity water and proteins, machinability, and weldability.

- Surface Finish Standards:

- Measured in Ra (arithmetic mean roughness), micro inches or micrometers.
- ASME BPE SF Code followed for specific finishes.

- Finish Types:

- Mechanical Only: Various Ra values from 10 to 30 microns, suitable for general applications.
- Mechanical + Electro-Polishing (EP): Offers smoother finishes down to 0.25 micrometers (10 Ra), ideal for stringent Life Science requirements.

- Body Types: Finishes are available for forged, wrought, and cast bodies.

- External Finish (OD): Standard finishes include mechanical polish or bead blasted; optional upgrades provide satin or mirror finishes for enhanced aesthetics and cleanability.

- Microbial Growth & Biofilm Prevention: Very smooth surfaces (below 0.42 µm Ra) are crucial for effective cleaning in place (CIP) and steam in place (SIP) processes, minimizing surface finish anomalies that can harbor microbes.

- Ra Values and Their Implications:

- 30 microns (Ra = 0.8 micrometers): Coarse finish, suitable for non-critical applications.
- 25 microns (Ra = 0.6 micrometers): Standard finish, offers a balance between strength and smoothness.
- Below 10 microns: Highly polished finishes required for critical Life Science applications to ensure maximum sterility and cleanability.