Article
In pharmaceutical, biotech, dairy, beverage and food plants, piping must do more than contain the fluid. It must protect product purity, be easy to clean and leave nowhere for bacteria to grow. Stainless steel, mainly 316L, is the standard material.
Why 316L?
- Excellent resistance to cleaning chemicals (CIP) and sterilisation (SIP) cycles
- Low carbon for good weld corrosion resistance
- Smooth, non-porous surface that can be polished
- 304L is used in less critical utility and food lines
Surface finish matters
| Application | Typical internal finish |
|---|---|
| General food and beverage | Ra ≤ 0.8 µm |
| Pharma process and purified water | Ra ≤ 0.5 µm, often electropolished |
| Utility lines | Pickled or mill finish |
Smoother surfaces are easier to clean and resist bacterial attachment. Electropolishing further improves the passive layer.
Sanitary tube vs process pipe
- Sanitary tube – ordered by OD and wall, to ASTM A270 or ASME BPE, with tight tolerances and polished finishes. Joined by orbital welding or tri-clamp fittings.
- Process pipe – ASTM A312 to NPS and schedule, used for utilities, CIP supply, steam and general process lines.
Hygienic design rules
- Avoid dead legs; keep branches short
- Slope lines for full drainage
- Use orbital welding with inert gas purging to avoid heat tint
- Pickle and passivate after fabrication
Documents buyers expect
- EN 10204 3.1 certificates with full heat traceability
- Surface roughness reports
- Ferrite and sulphur limits where ASME BPE applies
- Material declarations for food contact where required
Frequently asked questions
Which stainless grade is used in pharmaceutical piping?
316L is the standard, often with an electropolished internal surface.
What is ASME BPE?
The ASME Bioprocessing Equipment standard, covering design, materials, finishes and fabrication of hygienic process systems.
Can ASTM A312 pipe be used in food plants?
Yes, for utilities and many process lines; product-contact hygienic lines often use sanitary tube to ASTM A270 or ASME BPE.
Key takeaways
- 316L is the standard for hygienic piping.
- Internal surface finish (Ra) is a key specification.
- Use sanitary tube and orbital welding for product-contact lines.
Need these products?
Sawariya Metal Industries supplies stainless steel pipes, flanges and buttweld pipe fittings from Mumbai to buyers in India and overseas. Send your size, grade, standard and quantity through our enquiry form and we will reply with a clear quotation and the test documents you need. You can also browse our stainless steel pipes, flanges and buttweld fittings.