Lap-joint (loose) flange
The lap-joint flange with stub end (EN 1092-1 Type 04 + collar 34, LJ) sits loose on the welded stub end and rotates freely for alignment – ideal for frequently opened joints and for saving expensive materials. ROHRLINE supplies flanges of this type in carbon and stainless steel to EN 1092-1 and ASME B16.5 with EN 10204 3.1 inspection certificates – worldwide.
Application & design
The lap-joint flange with stub end (EN 1092-1 Type 04 + collar 34, LJ) sits loose on the welded stub end and rotates freely for alignment – ideal for frequently opened joints and for saving expensive materials.
- Frequently opened connections
- Stainless/special-material lines (cost saving)
- Plants needing tight alignment
- Chemical and process engineering
Technical overview
Standardised reference data. Please ask for availability of individual sizes and pressure ratings.
| Feature | Detail |
|---|---|
| Standards | EN 1092-1 (type 02 + collar 34) |
| EN 1092-1 type | 02 / 04 |
| Pressure ratings | PN 6 – PN 40 |
| Sealing faces | Form B1 / on collar |
| Nominal sizes | DN 10 – DN 600 |
| ASME equivalent | ASME B16.5 LJ + Stub End |
We supply Lap-joint (loose) flange to EN 1092-1, DIN and ASME – matched to pipe, material and pressure rating, on request with an EN 10204 3.1 / 3.2 mill certificate.
Flange dimensions PN 10 / PN 16
Outside diameter D, bolt circle K and bolts per nominal size to EN 1092-1 – applies to Lap-joint (loose) flange in PN 10 and PN 16 (identical up to DN 150). Other pressure ratings: flange dimension table.
| DN | Outside Ø D (mm) | Bolt circle K (mm) | Bolts (n × size) |
|---|---|---|---|
| DN 15 | 95 | 65 | 4 × M12 |
| DN 20 | 105 | 75 | 4 × M12 |
| DN 25 | 115 | 85 | 4 × M12 |
| DN 32 | 140 | 100 | 4 × M16 |
| DN 40 | 150 | 110 | 4 × M16 |
| DN 50 | 165 | 125 | 4 × M16 |
| DN 65 | 185 | 145 | 8 × M16 |
| DN 80 | 200 | 160 | 8 × M16 |
| DN 100 | 220 | 180 | 8 × M16 |
| DN 125 | 250 | 210 | 8 × M16 |
| DN 150 | 285 | 240 | 8 × M20 |
Frequently asked questions about Lap-joint (loose) flange
When to use a lap-joint flange?
When flanges are opened or aligned often, or to save costly stainless steel: only the stub end is of the pipe material, the loose flange can be cheaper steel.
Which standards apply?
EN 1092-1 Type 04 (loose flange) with stub end Type 34; in ASME the lap-joint flange with stub end.
Does the loose flange rotate?
Yes, it sits loose on the stub end and turns freely to align the bolt holes.
Request Lap-joint (loose) flange?
Type, size, pressure rating, sealing face and material are enough – we supply the right flange, on request with an EN 10204 3.1 / 3.2 mill certificate.
All data are typical values per EN 1092-1 / DIN / ASME for first orientation – without warranty. Please ask for the availability of individual sizes and pressure ratings. The applicable standard and the order confirmation are decisive.