SF Flanges
To maintain the internal diameter of your pipe when connecting to valves you need a Special Flange (SF), an engineered alternative to slim flanges with round holes.
SF flanges connect plastic pipe to fittings and steel flanges with matching nominal widths and pressure classes. The PE100 collar is designed as a fixed flange, backed by a stainless steel flange. This direct nominal-diameter approach lets you select the fitting one stage smaller than conventional loose flange connections, reducing project costs and simplifying installation while maintaining full pressure capacity.
The standard for valve connections and transitions to steel/cast flanges.
Key Properties
| Specifications | Details |
| Collar material | PE100 welding spigot (fixed flange design) |
| Backing flange | Stainless Steel or Steel with plastic coating or corrosion-free fibre-reinforced plastic (DIN EN 10310) |
| Hole pattern | AS4087 PN16 (other patterns on request) |
| Integrated Seal | EPDM O-ring as standard (flat face on request) |
| Welding methods | Butt fusion or Electrofusion |
| Pressure capacity | Full pressure load at matching nominal diameter |
| Optional versions | Short leg for butt welding only; DIN EN 1092–1 PN 25 design; stainless steel or galvanised backing flange; slotted holes in PE collar for perfect alignment; flat sealing without groove and O-ring |
| Standards | DIN EN 12201, DIN EN 1092–1, DVS 2207, DVS 2210, DIN EN 10204, DIN EN ISO 9001, DIN EN ISO 50001, DVGW W 400–2, DVGW GW 335, AS4087 PN16 |
| Approvals/certificates | DVGW: DV-8606BT0423 and DV-8611BT0424; DIN EN 10204 inspection certificate 3.1 on semi-finished product with MFR and OIT; PE100 material per PE100+ Association |
| Manufacturing | DIN EN ISO 9001 quality assurance; single-piece homogeneous PE moulded parts via injection moulding; DIN EN 10204 inspection certificates included |
Applications
SF flanges solve the problem of large-diameter transitions at DN/OD 160 mm and above. Conventional loose flange connections such as slim flanges or full-face flanges create significant cross-sectional changes that complicate installation and risk collar failure under pressure. SF flanges eliminate this offset by matching nominal diameters directly to valves and steel flanges.
Use SF flanges when you need:
Direct valve and steel flange connections without oversizing
Reduced project costs through smaller fitting selection
Simplified installation with lower deposit risk
Full pressure capacity across the same nominal diameter
Reliable long-term corrosion protection
