Bronze Loose Flanges Manufacturer & Exporter
Loose flanges are not fixed to the pipe. They bear against a collar, stub or lapped pipe end and are free to rotate for easy alignment of bolt holes.
What is a Loose flange?
A loose flange slides over the pipe and rests behind a welded collar, a lapped pipe end or a flared end. Only the collar or lapped end touches the medium; the flange simply applies the bolt load. The arrangement is similar in principle to the lap joint flange but covers a wider range of collar and flared-end constructions.
Loose flanges are used where it is helpful for the flange to be a different, often more economical, material than the pipe, or where the pipe end is formed rather than fitted with a stub end. They also make assembly of long pipe spools easier because holes can be aligned by rotation.
Construction
- Bore sized to clear the pipe and bear on the collar or lapped end
- Hubbed or plain profile as drawn
- Back face machined for even bearing
- Bolt holes to the specified pattern
- Thickness per standard or design
Values vary according to applicable specification, material condition and customer requirements.
Bronze Loose Flanges — specification
| Type | Loose (rotating) flange |
|---|---|
| Bears on | Collar, stub end or lapped pipe end |
| Bore | To suit pipe OD and collar dimensions |
| Pressure class | As defined by the applicable standard |
| 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 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 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 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
- Piping with formed or lapped pipe ends
- Systems requiring easy bolt-hole alignment
- Spool pieces fitted to fixed nozzles
- Assemblies where the flange is a different material from the pipe
See also: Shipbuilding · Industrial Piping · General Engineering.
Inspection and testing
- Bore and bearing-face dimensions
- Thickness and outside diameter
- Hole pattern (PCD) and bolt-hole size
- Surface and face finish
- Material identification and documents as agreed (MTC, inspection report, as applicable)
Made to your specification
Provide the collar or lapped-end drawing so the bore and seating face can be matched.
For non-standard dimensions, see custom & special flanges.
Related flange types
- Lap Joint FlangesA lap joint flange is a loose flange used together with a stub end.
- 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..
- Plate FlangesPlate flanges are flat rings with a bore and a bolt-hole pattern.
Have a Bronze Flange Requirement?
Send us your drawing, specification, material grade, size and quantity.