Plate Flat Welded Flange is an economical pipe flange manufactured by cutting high-quality steel plates and precision machining sealing faces and bolt holes. It is widely used in low to medium pressure pipeline systems where cost efficiency, easy installation and reliable sealing performance are required.
Compared with forged flanges, plate flanges offer shorter production cycles and flexible customization, making them ideal for EPC contractors, distributors and industrial maintenance projects.
This flange type is installed by inserting the pipe into the flange bore and performing double fillet welding on both inner and outer sides to ensure stable load distribution and vibration resistance.
Strict dimensional control ensures sealing surface accuracy and long service life.
Correct welding is essential to prevent leakage and deformation.
Recommended Welding Practice:
This welding structure provides adequate strength for general industrial piping systems.
| Feature | Plate Flange | Slip On Flange | Welding Neck Flange |
|---|---|---|---|
| Manufacturing | Plate Cutting | Forged | Forged |
| Strength | Medium | Medium-High | Very High |
| Cost | Low | Medium | High |
| Pressure Rating | Low-Medium | Medium | High |
| Installation | Very Easy | Easy | Complex |
| Application | General Pipelines | Process Lines | Critical Systems |
Plate flanges are preferred where fast installation and budget control are priorities.
| DN | Outside Diameter | Thickness | Bolt Circle | Bolt Hole |
|---|---|---|---|---|
| DN50 | 165 mm | 18 mm | 125 mm | 4-18 |
| DN80 | 200 mm | 20 mm | 160 mm | 8-18 |
| DN100 | 220 mm | 22 mm | 180 mm | 8-18 |
| DN150 | 285 mm | 24 mm | 240 mm | 8-22 |
| DN200 | 340 mm | 26 mm | 295 mm | 12-22 |
| DN250 | 395 mm | 26 mm | 350 mm | 12-22 |
| DN300 | 445 mm | 28 mm | 400 mm | 12-22 |
Full dimension tables for ASME / DIN available on request.
Pressure Class:
Size Range:
ASTM A105
A350 LF2
A694 F52 / F60
F304 / 304L
F316 / 316L
F321
F904L
S31803
S32205
S32750
Inconel 625
Inconel 825
Monel 400
Hastelloy C276
Plate flanges supplied for:
(Custom project references available upon request.)
What is the advantage of plate flange?
Lower cost and faster production compared with forged flanges.
Can plate flange be used in high pressure systems?
Generally recommended for low to medium pressure pipelines.
Is welding required during installation?
Yes, double fillet welding is required to secure the pipe connection.
