Sanitary Stainless Steel Din 11864-1 Nuts: Design Features And Applications

For biopharmaceutical piping, specify the DIN 11864-1 nut (standard, DN10-DN100, SS304) to replace NPT threaded connections. This design eliminates dead legs and crevices. The O-ring face seal provides a cleanable interface. Installation requires two standard wrenches. Tighten to the specified torque. Inspect O-ring before assembly. Select SS304 for standard bioprocess applications. The connection supports CIP and SIP protocols.

The Problem with Standard Threaded Connections

Standard NPT threads create spiral leak paths and fluid traps. These allow microbial growth in dead legs. Thread sealant particles can shed into product streams. Crevice corrosion occurs in thread roots over time.

Contamination risks:

• Dead legs – fluid traps retain product residues.

• Thread crevices – harbor bacteria that survive cleaning.

• Sealant particles – shed into process lines.

• Corrosion – crevice corrosion in thread roots.

The din11864 standard defines dimensions and tolerances for aseptic threaded connections. The DIN 11864-1 nut addresses these risks through its crevice-free profile.

DIN 11864-1 Design Features

The DIN 11864-1 fitting uses a flat face flange with an O-ring seated in a groove on the nut face. When tightened, the flanges compress the O-ring, creating a seal. No threads exist in the product-contact area. Standard configuration ensures interchangeability with existing components.

Specifications:

• Material: SS304

• Connection: Threaded union

• Size range: DN10 – DN100

• Pressure rating: Up to 16 bar

• Temperature: -10°C to 135°C

• Type: Standard (not custom)

The din 11864 1 variant is the union nut design for connection to corresponding flanges. This ensures interchangeability within the DIN11864 family.

Comparison: DIN 11864-1 vs. NPT Threads

Installation and Maintenance

Installation requires two wrenches—one to hold the flange, one to tighten the nut. The O-ring seats into the flange groove. Proper torque ensures seal integrity. No lubrication or sealant is applied to threads. Standard sizing (DN10-DN100) covers common biopharmaceutical piping.

Installation steps:

1. Inspect O-ring for damage.

2. Align flange faces.

3. Thread nut onto mating flange.

4. Tighten to the specified torque.

5. Verify seal integrity.

The din 11864 2 design features an O-ring with retaining ring. The din 11864 3 version offers a different arrangement for specific installation requirements. All three variants maintain the same aseptic principles.

Material Selection

The nut is manufactured from SS304 stainless steel, suitable for standard bioprocess applications. The interior surface is machined to a smooth finish, preventing product adhesion and simplifying cleaning.

• Body material: SS304

• Surface finish: Ra ≤ 0.8μm

• O-ring materials: EPDM, FKM, or PTFE

• Standards: DIN 11864-1, ASME BPE, 3A, FDA

SS304 provides corrosion resistance for purified water, buffers, and mild CIP chemicals. For more aggressive conditions, SS316L may be specified.

Applications in Biopharmaceutical Lines

The DIN 11864-1 nut is specified at connections requiring disassembly for cleaning or maintenance. The DN10-DN100 range covers from lab-scale to production lines.

Typical installation points:

• Bioreactor feed and harvest lines

• CIP supply and return connections

• Filtration skid inlet and outlet

• Chromatography column connections

• WFI distribution loops

These connections replace threaded pipe fittings that are not acceptable for hygienic service. The din11864 standard is recognized in Europe for biopharmaceutical and food processing applications.

Why Specify DIN 11864-1 Connections

1. Eliminates dead legs and crevices in threaded connections.

2. Uses O-ring face seal without sealant compounds.

3. Provides SS304 construction for standard bioprocess applications.

4. Supports CIP and SIP protocols.

5. Enables tool-based assembly with standard wrenches.

The DIN 11864-1 nut is a solution for biopharmaceutical connections requiring aseptic threaded fittings. Its design replaces conventional NPT threads with a crevice-free connection. The din 11864 1, din 11864 2, and din 11864 3 variants cover different assembly configurations within the same standard. Specify this connection for transfer lines and process equipment where contamination control is required.

DIN 11864-1 Nut

• DIN11864 aseptic fittings meet the exacting needs of food, chemical and pharmaceutical industries.
• Available with optional lengths to suit Orbital and Manual Welding, these unions have been designed to match tube and pipe specifications in DIN 11850; ISO 2037, ASME BPE 2002 and BS 4825 Part 1 and also ISO 1127 for schedule pipe.
• DIN11864-1 union consists of four parts: Nut, Male, Liner and Gasket.

Product Description

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