Food grade stainless steel and other metals for dairy, food and beverage plants

Bulk milk coolers, silos, pasteurisers, holding tubes and ice-cream freezers are mostly 304 stainless. It has 17.5–19.5% chromium and 8–10.5% nickel, does not react with milk fat or lactic acid at dairy temperatures, and handles the hot caustic and nitric acid of daily CIP well. Karnataka has a large cooperative dairy network with chilling centres spread across the districts, and most of that equipment is 304 sheet, pipe and fittings.

Where 304 runs into trouble in a dairy is chlorinated cleaning. Hypochlorite sanitisers left too long or too hot cause pitting, so plants that rely on them should move contact parts to 316L.

Brine tanks, cheese brining, pickles, tomato products, citrus juices, sauces and ready meals with salt all push the chloride level up. 316 or 316L adds 2–3% molybdenum, which is what resists chloride pitting. The extra cost is usually 20–30% on material and far less on the finished machine, so it is easy to justify on any line handling salt.

Bangalore's breweries and microbreweries are mostly stainless in fermenters, bright tanks and pipework, generally 304. Copper still has a place: traditional brew kettles and many spirit stills use it because copper strips sulphur compounds out of the vapour and improves flavour. Our copper sheets and plates are used by fabricators for exactly this kind of work.

Soft drink and packaged water plants are 304 or 316L depending on the product, with 316L preferred for anything carbonated and acidic.

Utility lines behind the process are a different matter. Glycol chilling, compressed air and CO₂ lines in a brewery are often 304 pipe with screwed or welded fittings, while steam to the brewhouse runs in carbon steel. Separating process and utility lists on the indent keeps the expensive grade where it belongs.