DN32 DIN 1.4404 (AISI 316L) Sanitary Nut-type Hose Coupling

DIN Sanitary Nut-type Hose Coupling  

Dimensions & Sizes

Core Principles of DIN 11866 for Sanitary Fittings

The DIN 11866 series is the authoritative European standard for sanitary tubing systems. Its core design philosophy is to create a system free of dead legs, which is easy to clean and sterilize thoroughly, specifically for the food, dairy, pharmaceutical, and cosmetic industries.

Dimensions and Tolerances: The standard strictly defines external diameter and wall thickness series, ensuring excellent interchangeability between components from different manufacturers. The preparation of weld ends (e.g., bevels) must also follow specifications to guarantee perfect internal alignment and smooth transition during welding.

Materials: The standard specifies the use of stainless steel conforming to DIN EN 10357 or DIN 17472, primarily grades 1.4404 (AISI 316L) and 1.4301 (AISI 304). These materials must possess excellent corrosion resistance and formability.

Surface Finish: The standard requires product contact surfaces to be smooth and free of defects. The typical delivery condition is mechanical polishing, with an internal surface roughness typically required to be Ra ≤ 0.8 µm. This level of finish effectively prevents microbial adhesion and facilitates CIP cleaning.

Hygienic Design: All fittings must be designed following the no-dead-leg principle. Butt-welded seams must achieve a flush interior; any internal weld reinforcement must have a smooth transition, and concavity is strictly prohibited, eliminating crevices that could trap media at the source.

Connection Type: Fittings conforming to DIN 11866-3 are designed for butt-weld connections, enabling seamless and clean system integration via automatic orbital welding.