All about DIN 11851 connections: hygienic, reliable and versatile.

DIN 11851 is a widely used standard for hygienic Stainless steel fittings, used in the food, beverage and chemical industries. Thanks to its well-designed construction, this type of coupling is easy to assemble and disassemble, easy to clean (CIP-compatible), and meets the highest standards in hygiene, safety and reliability.

What does a DIN 11851 coupling consist of?

A complete DIN 11851 coupling consists of four parts:

• Male – with conical sealing surface
• Liner – with external thread and sealing groove
• D-ring – available in various materials
• Nut – ensures a secure connection

The conical seal and special D-ring ensure a leak-proof, safe, and easy-to-clean connection.

Material and surface finish

DIN 11851 couplings are manufactured from stainless steel forgings 304(L) or 316(L), in accordance with DIN EN 10254, or from semi-finished products according to DIN EN 10088-3. The internal surface has a roughness of max. Ra ≤ 0.8 μm, and the external surface max. Ra ≤ 1.6 μm, minimizing dirt adhesion and bacterial growth.

Seals (D-rings)

The seals are available in various elastomers and plastics, tailored to different chemical and thermal conditions:

Dimensions and pressure ratings

DIN 11851 couplings are available in several standard versions:

• DIN – EN 10357 Series A (DN 10 to DN 200)
• ISO – EN 10357 Series C (DN 10 ISO to DN 150 ISO)
• INCH – EN 10357 Series D (1" to 4")

The maximum allowable working pressure (MAWP) depends on the nominal diameter:

• DN 10 to DN 40: up to 40 bar
• DN 50 to DN 100: up to 25 bar
• DN 125 to DN 150: up to 16 bar

Advantages of DIN 11851 couplings

• Hygienic design with smooth surfaces
• Easy to assemble and disassemble
• Versatile for use in food and chemical industries
• Durable, robust and corrosion-resistant
• Compatible with existing systems

Traceability

All Rodesta couplings are marked with size, material grade and heat number for full traceability.

Upon request, we provide:

• Material certificate 3.1 according to EN 10204:2004
• Material conformity declaration 2.1 according to EN 10204
• Declaration of conformity according to FDA and/or EC 1935/2004

Conclusion

DIN 11851 couplings are a reliable choice for hygienic applications in the food, beverage and chemical industries. Thanks to their robust design, simple assembly and excellent cleanability, they meet the high demands of modern process installations. Rodesta offers a complete range of DIN 11851 components, including seals and accessories, directly from stock.

Frequently Asked Questions (FAQ)

What are DIN 11851 couplings used for?

DIN 11851 couplings are commonly used in the food, beverage and chemical industries due to their hygienic design, ease of assembly and excellent cleanability.

What is the difference between DIN, ISO and INCH versions?

The difference lies in the dimensions and fit. DIN uses metric dimensions (DN), ISO is based on international standards, and INCH refers to inch-based sizing. They are not interchangeable.

Which seal should I choose for my application?

That depends on the medium, temperature and cleaning method. EPDM is suitable for CIP, PTFE for aggressive chemicals, and VMQ (silicone) for applications requiring taste or odor neutrality. Our specialists are happy to advise you.

Are DIN 11851 couplings suitable for CIP?

Yes, the conical design and smooth surfaces make these couplings highly suitable for Clean-in-Place (CIP) cleaning.

Do you also supply documentation?

Yes. On request we provide material certificates (3.1), declarations of conformity (2.1), and documentation in accordance with FDA or EC 1935/2004.

Rodesta supplies a wide range of DIN 11851 components from stock, in DIN, ISO and INCH dimensions, including bends, reducers, end caps and seals.Need advice on the right coupling for your application? Our specialists are happy to help.Download our DIN 11851 - Catalogus here.