Plate flange slipped over the pipe and fillet-welded both sides — the economical standard flange.
| Size range | DN15–DN2000 |
|---|---|
| Pressure class | PN2.5–PN25, Class 150–600 (higher classes on request) |
| Standards | HG/T 20592-2009, GB/T 9119, JB/T 81, ASME B16.5, ASME B16.47 |
| Face types | RF, FF |
| Welding | Single-side fillet weld outside, plus inside fillet where accessible |
| Bore | Machined to clear the ordered pipe outside diameter |
The slip-on flange slides over the pipe end and is fillet-welded on both faces. It is cheaper than a weld neck, easier to align, and perfectly adequate for most low and medium pressure utility and process connections in stainless and alloy service.
Lower cost and shorter lead time than a weld neck at the same pressure class.
The flange can be rotated before welding, which simplifies bolt-hole alignment on site.
Thicker hub than a plate flange gives a stiffer ring and a better distribution of bolt load.
Not for severe cyclic service, high vibration or where the weld will see repeated bending — the double fillet has lower fatigue resistance than a butt weld.
Above Class 600 or in hydrogen service, use a weld neck.
Long-hub WN flange butt-welded to pipe, for high pressure and cyclic service.
Specifications
Rotating loose flange used with a stub end — easy bolt-hole alignment and cheap to replace.
Specifications
Small-bore socket weld flange, single external weld, DN6–DN100.
SpecificationsQuotes within one business day. Send grade, size, pressure class, face type and quantity — a drawing works better than a description.
