Nickel Alloy Flat Face Flanges

Flat face flanges (FF flanges) are flange types with a complete flat sealing surface. Featuring large sealing surface area, easy gasket installation, and suitability for cast iron equipment and low-pressure applications, they are widely used in water treatment, low-pressure chemical piping, fire protection systems, HVAC, and general industrial connections. The nickel alloy flat face flanges supplied by us are manufactured from high-quality nickel-based alloy forgings or plates through multiple precision processes including forging/cutting, solution heat treatment, machining, drilling, and pickling/passivation. Featuring flat sealing surface, high machining precision, excellent corrosion resistance, and easy installation, they are specifically designed for low-pressure, non-critical applications or connections with cast iron equipment.

Application Notes:

1. Flat face flanges are typically used for low-pressure applications up to Class 150
2. Particularly suitable for connections with cast iron valves, pumps, and equipment
3. Can use full face gaskets (non-metallic gaskets, rubber gaskets, etc.)

Supply Range

Flange Type: Slip-On, Plate Flange, Hubbed Slip-On, Blind

Nominal Diameter (DN/NPS): DN15 – DN600 (1/2 inch – 24 inches); Larger diameters up to DN3000 negotiable

Pressure Class: Class 150 (ASME); PN 6, PN 10, PN 16, PN 25 (EN)

Machining Precision: Sealing surface roughness Ra 3.2μm – 6.3μm (higher available upon request)

Surface Condition: Machined, Pickled optional

Marking: Steel stamp marking on flange outer edge, conforming to MSS SP-25 or customer requirements

Dimensional Inspection

1. Overall Dimensions: Measuring all critical dimensions using calipers, micrometers, tape measures
2. Sealing Surface Flatness: Measuring using surface plates and feeler gauges
3. Bolt Holes: Inspecting hole diameter, bolt circle, hole position
4. Bore Diameter: Measuring bore size ensuring pipe matching

Appearance Inspection

1. Sealing Surface: Inspecting for scratches, pits, rust
2. Surface Quality: Visual inspection, no cracks, folds, laps, or other defects

Non-Destructive Testing

1. Penetrant Testing (PT): 100% inspection of sealing surface and critical areas
2. Ultrasonic Testing (UT): Inspection for critical service flanges

Stock Availability

We maintain inventory of common specifications for mainstream grades such as Inconel 600/625, Monel 400, and Hastelloy C-276 flat face flanges.

Related ranges: dimensional and standards background for this product is set out in our nickel alloy butt weld fittings. See also our Flanges. Each range is listed with its governing ASTM and ASME specification.