Short answer: Chemical and pharmaceutical plants need stainless that resists acids, chlorides, and clean-in-place chemicals. 316L is the hygienic default for pharma; 304L serves less aggressive lines. Duplex 2205 handles chlorides and seawater, while 904L resists strong acids. Specs follow ASTM A270, A312, A790, and A182.
At a Glance
Grade Selection for Process Plants
As the chart shows, 304L suits general, non-critical piping. 316L is the workhorse for hygienic and mildly corrosive service thanks to its molybdenum. Duplex 2205 is specified where chlorides, stress-corrosion cracking, or high pressure dominate, and 904L is reserved for strong acid duty.
Hygienic Pharma Specification
Biopharma lines use 316L with an electropolished inside diameter (Ra ≤ 0.5 µm) and orbital-welded, crevice-free joints to ASTM A270 / 3A. Surfaces must withstand aggressive CIP/SIP cycles without rouging or pitting.
Standards and Forms
- ASTM A312 / A269: seamless and welded pipe and tube for general service.
- ASTM A270: sanitary tubing for food and pharma.
- ASTM A790 / A182: duplex pipe, tube, and forgings.
- ASTM B677: 904L seamless pipe and tube.
HXSCO supplies these forms in seamless e welded construction with mill-test reports.
Corrosion Considerations
Chloride is the main enemy: even 316L can pit above a few thousand ppm chloride or in hot concentrated service. Duplex 2205 and super-austenitic 904L extend the envelope. For sulfuric or phosphoric acid, 904L is often preferred. Always confirm the exact media, concentration, and temperature with your supplier.
Sourcing Process-Grade Stainless from HXSCO
HXSCO can source 304L, 316L, duplex 2205, and 904L in plate, pipe, tube, and forgings with full mill certificates and third-party inspection. Send your P&ID or spec for a project-specific quote.
Perguntas frequentes
316L is the standard for hygienic pharma lines because of its corrosion resistance and cleanability; 304L is used for less aggressive service.
316L contains molybdenum, giving far better resistance to chlorides and many chemicals. 304L is fine only for mild, low-chloride environments.
Where chlorides, stress-corrosion cracking, or high pressure are present — reactors, seawater cooling, and heat exchangers.
904L is a super-austenitic grade for strong acids such as sulfuric and phosphoric, where 316L would corrode.
ASTM A270 and 3A for sanitary tubing; A312/A269 for general process pipe; A790/A182 for duplex; B677 for 904L.
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Request a QuoteWhy Buyers Trust HXSCO for Stainless Steel
HXSCO is a stainless steel supplier serving manufacturers, fabricators, and trading companies worldwide. We stock 304, 304L, 316, 316L, 430, 201, and duplex grades in plate, sheet, coil, pipe, tube, bar, wire, and rod forms. Every order can be supplied with mill-test certificates, third-party inspection, and custom cutting/shearing to your drawing. Contact HXSCO for a project-specific quote or material recommendation.