Bronze Reducing Flanges Manufacturer & Exporter
A reducing flange connects a pipe of one nominal size to a mating flange of a different, larger size, using a single flange with a reduced bore.
What is a Reducing flange?
A reducing flange has the face, bolt-circle and drilling of the larger flange but a bore sized for the smaller pipe. Bolted to a larger mating flange, it changes the line size at the joint without a separate reducer fitting, which saves length and a joint in compact installations.
The reduction available is limited by flange design and by the piping code: very large reductions are normally handled with a reducer fitting instead. Reducing flanges are most often used on pump and valve nozzles, equipment connections and compact skid pipework.
Construction
- Face and drilling of the larger nominal size
- Bore (and socket or thread, if any) of the smaller pipe size
- Thickness per standard or design for the larger face
- Hub or hubless profile as specified
- Face and finish as specified
Values vary according to applicable specification, material condition and customer requirements.
Bronze Reducing Flanges — specification
| Type | Reducing flange (larger face, smaller bore) |
|---|---|
| Face / drilling | Larger nominal size |
| Bore | Smaller nominal size or custom |
| Connection | Slip-on, socket, threaded or plate style, as drawn |
| Sizes | As per customer requirement / applicable standard |
| Pressure classes | Pressure classes and pressure-temperature ratings are defined by the standard applied and depend on alloy and temperature. Available as per applicable material and dimensional standard. |
| Facing options | Flat face (FF), raised face (RF) or custom facing as specified by the standard or drawing. |
| Standards | Typical reference standards for copper-alloy flanges include ASME B16.24 (cast copper alloy pipe flanges and flanged fittings), MSS SP-106 (cast copper alloy flanges and flanged fittings) and EN 1092-3 (copper alloy flanges). Customer drawings and other national or project standards are also worked to. The standard to be applied is confirmed when the enquiry is reviewed. |
|---|---|
| Dimensions | Outside diameter, thickness, bore, bolt-circle diameter, number and size of holes per the standard or customer drawing. Available as per applicable material and dimensional standard. |
Available bronze materials
Available as per applicable material and dimensional standard. Select a grade for composition limits, mechanical properties and corrosion notes.
| UNS grade | Alloy family | Note |
|---|---|---|
| UNS C83600 | Leaded red brass / composition bronze (Cu-Sn-Pb-Zn) | UNS C83600 — commonly called gunmetal, composition bronze or red bronze — is the traditional general-purpose cast alloy for valves, pump parts and pipe fittings, and the material behind our gunmetal flanges. |
| UNS C95800 | Nickel aluminium bronze, NAB (Cu-Al-Ni-Fe-Mn) | UNS C95800 is the standard cast nickel aluminium bronze for seawater service. |
| UNS C95400 | Aluminium bronze (Cu-Al-Fe) | UNS C95400 is a heat-treatable aluminium bronze that combines high strength with good wear and corrosion performance, making it a common choice for demanding pump, valve and marine components. |
| UNS C93200 | Leaded tin bronze (Cu-Sn-Pb-Zn) | UNS C93200 is a leaded tin bronze widely used where free machining, good pressure tightness in castings and bearing behaviour matter more than very high strength. |
| UNS C63000 | Wrought nickel aluminium bronze (Cu-Al-Ni-Fe-Mn-Si) | UNS C63000 is a wrought (not cast) aluminium bronze. |
Where these flanges are used
- Pump suction and discharge connections
- Valve and equipment nozzle size changes
- Compact skid and packaged systems
- Retrofit connections to existing flanged equipment
See also: Pumps & Valves · OEM Equipment · Industrial Piping.
Inspection and testing
- Bore and face dimensions against both sizes
- Thickness and outside diameter
- Hole pattern (PCD) and bolt-hole size
- Face flatness and finish
- Material identification and documents as agreed (MTC, inspection report, as applicable)
Made to your specification
Please specify both nominal sizes, the connection type for the smaller bore and the standard of the mating flange.
For non-standard dimensions, see custom & special flanges.
Related flange types
- Slip-On FlangesSlip-on flanges are machined from bronze and copper-alloy grades so that the pipe slides into the bore and is secured by fillet welding or brazing, depending on material and procedure..
- Threaded / Screwed FlangesThreaded flanges connect to pipe through an internal thread, avoiding welding at the joint.
- Custom / Special FlangesSend your drawing, sample or specification.
Have a Bronze Flange Requirement?
Send us your drawing, specification, material grade, size and quantity.