Sanitary And Aseptic Flange Fitting Material Selection And Application (din11864-2)

A hygienic stainless steel aseptic DIN11864-2 flange connection uses a machined O-ring groove and a metal centering shoulder to seal without gaps. The O-ring sits in the groove, and the shoulder limits compression when the flanges meet. This removes the crevice where product can lodge, so the joint cleans fully during CIP and SIP. The body uses SS316L with a flange-weld connection, rated from -20°C to 120°C at 0-10 bar.

Sealing Groove and O-Ring Cavity

The flange face carries a machined groove that holds the O-ring in place. The groove depth sets the compression rate when the flanges close. A metal shoulder stops the faces at the designed gap.

• Machined groove holds the O-ring

• Groove depth sets compression rate

• Metal shoulder limits closure

• Seal sits inside the cavity, not on a flat face

A flat gasket joint leaves a step at the bore edge. Product collects in that step and resists flushing. The recessed groove removes the step, so the wetted path runs smooth.

Three Connection Forms in the Standard

The din11864 standard covers three parts with the same sealing principle. The din 11864 1 form uses threads, din 11864 2 uses flanges, and din 11864 3 uses clamps.

Each form shares the same Form A groove, so a system can switch connection style at any node and keep seal performance consistent.

Material and Surface Requirements

Wetted parts use SS316L (1.4435 or 1.4404). Ferrite content is controlled to protect weld zones from corrosion. Internal roughness reaches Ra ≤ 0.8 μm, and electropolishing lowers it toward Ra ≤ 0.4 μm.

O-ring compounds include EPDM, PTFE, and FFKM. EPDM suits steam sterilization, PTFE handles aggressive chemistry, and FFKM covers higher temperature with corrosive media.

Pressure and Temperature Limits

Flange unions carry pressure ratings by bore size. The flange-weld end joins the flange to the pipe by welding, so the joint holds line load without a clamp. Working temperature follows the O-ring compound, and standard elastomers cover -20°C to 120°C.

Confirm the sterilization temperature against the seal rating before selection. A seal used above its limit hardens and loses compression.

Installation and Maintenance Steps

1. Inspect the O-ring for cuts or deformation.

2. Clean the metal centering face of particle residue.

3. Seat the O-ring in the machined groove.

4. Bring the flanges together until the metal faces touch.

5. Check O-ring compression set at service intervals.

Metal-to-metal contact sets the design compression. Extra bolt torque adds no seal benefit and can damage the groove edge.

Common Applications

Flange connections serve lines that need a fixed joint with full drainability. The aseptic face suits sterile process piping.

• Pharmaceutical process manifolds

• Biotech fermentation headers

• Sterile transfer panels

• WFI and clean steam lines

• CIP and SIP supply circuits

A din11864 flange joint suits larger bore connections where a threaded or clamped end would not hold the line load.

O-Ring Replacement and Traceability

Replace the O-ring at each scheduled rebuild, even when it looks intact. Compression set builds over sterilization cycles and reduces sealing force. Match the compound to the process medium and the SIP temperature. Record the batch number of each O-ring so a seal failure can be traced to its source lot. Store spare rings in sealed bags away from UV light and ozone.

DIN 11864-2 Aseptic Flange Connection

• DIN 11864-2 is a gap-free connection that has been specially designed with sterile applications in mind.
• The DIN11864-2 stainless fittings are available in practically all sizes and standard configurations. With these flanges means the process conditions are optimized inside for sterility and cleaning processes whilst ensuring the highest safety to the environment.
• All DIN11864-2 aseptic stainless flanges have a smaller outer diameter and are very compact. The design of these aseptic stainless unions incorporates the use of a standard dimension o-ring which gives the flexibility of material choice.

Technical Data

Product Parameter