Slip-On Bronze Flanges Manufacturer & Exporter

Product Overview

Slip-on is the general-purpose flange for copper-alloy and seawater pipework. The bore is machined slightly larger than the pipe outside diameter, so the pipe is inserted from the back, positioned, and secured with a brazed or welded joint. Compared with a threaded flange there is no thread to cut or seal, and compared with a socket-weld flange there is no fixed insertion depth to control.

Technical Description

A slip-on flange depends on the quality of the brazed or welded joint rather than on a threaded or socketed seat. Joint design, filler metal and procedure are therefore set by the piping specification, not by the flange alone. Leaded grades such as C83600, C84400 and C93200 are normally brazed rather than welded; aluminium bronze grades are welded to qualified procedures with matching filler.

Construction

• Bore sized to clear the pipe outside diameter, with the fit tolerance stated on the drawing
• Hubbed, low-hub or flat-back profile, depending on the standard or drawing
• Flat face (FF) or raised face (RF) gasket seating surface
• Bolt holes on the specified bolt circle (PCD); hole count and diameter per the class table
• Optional pipe stop or counterbore for repeatable insertion depth

Available Materials

Dimensions and Sizes

Outside diameter, thickness, hub dimensions, bore and bolt circle come from the governing standard or from your drawing. The table below lists the ASME B16.5 Class 150 bolt pattern that bronze flanges commonly use to mate with standard counter-flanges. Thickness, hub and facing dimensions are not listed because they differ between flange standards. Confirm every dimension against the standard or drawing named on your purchase order.

Sizes

Nominal pipe size (NPS) and class follow the governing standard; custom bore and OD are made to drawing. Quote requests should give size and class together, for example “NPS 4, Class 150, RF.”

Pressure Classes

Pressure class — typically Class 150 or Class 300 for copper-alloy flanges under ASME B16.24 or MSS SP-106 — is stated on the purchase order. The allowable working pressure depends on the alloy and the operating temperature in the governing standard, so we do not quote a single rating that ignores either.

Facing Options

Flat face and raised face are the standard options. The contact-face finish can be machined to MSS SP-6 or to a roughness you specify. Gasket type and bolting should be agreed at the RFQ stage so the face is machined for the intended gasket.

Applications

• Seawater cooling and fire-main branches
• Pump suction and discharge connections
• Valve end connections on copper-alloy pipework
• Water-treatment and process-water headers

• Marine
• Pumps
• Seawater Systems

Manufacturing

Blanks are cast or machined from wrought stock depending on grade and specification — for example ASTM B148 castings for aluminium bronze or ASTM B62 for C83600. Operations include turning the face, back and OD, boring, drilling the bolt circle and finishing the contact face, with hub profile and pipe stop machined to drawing.

Inspection and Documentation

Visual and dimensional checks cover OD, thickness, bore, PCD, hole diameter and spacing, and face finish. Material is verified against the grade and specification, with a Material Test Certificate (MTC) where required. Hardness, liquid penetrant or radiographic examination and pressure testing are carried out only when the purchase order calls for them.

Custom Requirements

Special hub lengths, counterbores, reduced bores, non-standard drilling (ASME, EN/PN, JIS or custom), added tapped holes and customer marking. Send the print or specification and we will confirm what can be made.