Buy Rubber Bellows Online in Australia
What Is a Rubber Bellows?
A rubber bellows — also called a rubber expansion joint or flexible pipe coupling — is a flanged, flexible pipe section fitted between two rigid pipe runs. Its rubber body, reinforced internally and finished with flanges at each end, absorbs vibration, thermal movement and minor misalignment while still containing line pressure. It's typically fitted at pump suction and discharge, across long thermal-expansion runs, and anywhere vibrating equipment connects to fixed pipework.
AIMS Industrial stocks AAP rubber pipe bellows in EPDM and NBR rubber compounds, sized from 1-1/4" (DN32) up to 24" (DN600) depending on the model, with Table-D, Table-E, ANSI 150 or BS 4504 PN16 flange faces to suit common Australian and international piping standards.
Rubber Pipe Bellows at AIMS — Quick Reference
| Product | Material | Flange standard | Size range |
|---|---|---|---|
| AAP EPDM Rubber Bellow Table-E | EPDM | Table-E (AS 4087) | 1-1/4" (DN32) – 24" (DN600) |
| AAP NBR Rubber Bellow Table-E | NBR | Table-E (AS 4087) | 2" (DN50) – 6" (DN150) |
| AAP EPDM Rubber Bellow Table-E x BS4504 PN16 | EPDM | Table-E / BS 4504 PN16 (dual-drilled) | 1-1/4" (DN32) – 8" (DN200) |
| AAP NBR Rubber Bellow ANSI 150 | NBR | ANSI 150 (ASME B16.5 Class 150) | 2" (DN50) – 5" (DN125) |
| AAP 250mm (10") EPDM Rubber Bellow Table-D — RB250D | EPDM | Table-D (AS 4087) | 250mm (10" / DN250) — fixed size |
Materials — EPDM vs NBR
EPDM (Ethylene Propylene Diene Monomer) rubber is the right choice for water service, cooling circuits, steam and most aqueous chemical applications. EPDM resists heat, weathering and ozone well, but it is not suited to mineral oil, fuel or hydrocarbon service — those will swell and degrade EPDM rubber over time.
NBR (Nitrile / Buna-N) rubber is the standard choice for oil and fuel service — diesel, hydraulic oil, lubricating oils and other petroleum-based media. NBR has poorer weathering resistance than EPDM, so for outdoor pipework carrying water, EPDM is the better pick.
Material selection matters more than most people expect on this product: get it wrong and the usual outcome is a leak and unplanned downtime, not a slow warning sign. If you're not sure which compound suits your media, check with our team before ordering.
Flange Standards — Table-D, Table-E, ANSI 150 & BS 4504 PN16
Table-D and Table-E are flange tables under AS 4087, the Australian standard for ductile iron pipe flanges widely used in municipal water, wastewater and irrigation pipework. Table-D is the lower-pressure-duty table; Table-E is the higher-duty option and, in many common sizes, shares its bolt-hole pattern with BS 4504 PN16 — which is why some bellows are supplied dual-drilled as "Table-E x BS4504 PN16".
ANSI 150 (ASME B16.5 Class 150) is the US-derived flange standard common on process plant, chemical piping and imported pump skids.
BS 4504 PN16 is the European metric standard — PN16 denotes a 16 bar nominal pressure class — common on imported European pumps and process equipment.
Table-D, Table-E, ANSI 150 and BS 4504 PN16 flanges are not dimensionally interchangeable with each other, so always match the standard already on your pipework rather than assuming.
Common Applications
- Pump suction and discharge — absorbs pump vibration before it transmits into rigid pipework, extending pipe and fitting life
- HVAC chilled water and condenser circuits — accommodates thermal expansion across long pipe runs
- Cooling tower circuits — handles thermal cycling and equipment vibration
- Chemical and water/wastewater process pipelines — absorbs movement at vessels, exchangers and pump skids
- Diesel and fuel transfer (NBR only) — pump skids, generator fuel lines, fuel transfer lines
Selecting the Right Rubber Bellows
Work through these in order to avoid a return trip:
- Flange standard first — match the flange table already on your pipework: Table-D or Table-E for Australian ductile-iron water-industry systems, ANSI 150 for US-derived process plant, or BS 4504 PN16 for European-standard equipment. A bellows drilled to the wrong standard won't bolt up, regardless of nominal size.
- Nominal size — must match the pipe or equipment flange it's connecting to. Check the table above for the size range each model covers.
- Face-to-face length — check the installed length against the gap in your pipework before ordering; this isn't interchangeable between different bellows designs, even at the same size.
- Movement type and capacity — confirm the axial, lateral and angular movement your application needs falls within the model's design range. Bellows absorb movement within published limits — they're not designed to correct gross misalignment.
- Elastomer vs the media — EPDM for water, steam and most aqueous chemicals; NBR for oil, fuel and hydrocarbons.
- Temperature — check your line's operating temperature, including start-up or cleaning excursions, sits within the elastomer's practical range (EPDM typically handles higher heat than NBR).
Unsure which combination you need? Call our team on (02) 9773 0122 or contact us with your pipe standard, size and application — we'll help you get the right part first time.
Installation & Replacement Tips
Two rules matter more than any other with this product. First, a bellows must not be used to correct gross pipework misalignment — it's built for movement absorption, not joint repair. Second, anchor and guide brackets should be fitted either side of the bellows to stop pressure thrust extending the unit beyond its design movement; on high-pressure or large-bore lines, control rod assemblies may also be needed to limit elongation under fault conditions.
When replacing an existing bellows, check for surface cracking, bulging, ply separation or leakage at the end flanges — these are the usual signs it's due. Outdoor installations exposed to UV tend to degrade faster than indoor ones. Plan replacement at the first sign of wear during scheduled maintenance rather than after a failure takes the line down.
Brands Stocked at AIMS
AAP is the brand behind every rubber bellows in this range — all five products here are supplied by AAP. If you need help matching an AAP bellows to an existing installation or another brand's spec, our team can talk you through it.
Companion Ranges at AIMS
Rubber bellows sit within our broader pipes, tubes & fittings range. For threaded pipe connections, see pipe fittings. For sealing and gasket selection, see gaskets. For hose-based flexible connections, see hoses and hydraulics. For rotary shaft seals, see oil seals & O-rings.
Frequently Asked Questions
What's a rubber bellows?
A rubber bellows — also called a rubber expansion joint or flexible coupling — is a flexible pipe section that absorbs vibration, thermal expansion and misalignment in piping systems. A rubber body with internal reinforcement and end flanges allows it to flex while still containing line pressure. It's used across pump, HVAC and water/wastewater pipework to isolate machinery from rigid pipe and reduce vibration transmission.
When do I need a rubber bellows?
Anywhere a pipe connects to vibrating equipment — pumps, compressors, chillers, generators — a bellows absorbs the vibration and prevents pipe stress. It's also used for thermal expansion compensation on long pipe runs and to tolerate minor misalignment during installation. Without one, vibration transmitted into rigid pipe typically shows up as flange leaks, support failures and, over time, pipe cracking.
EPDM or NBR — which rubber for which fluid?
EPDM suits water, steam, hot water systems and most mild aqueous chemicals. NBR (nitrile) suits oils, fuels and hydraulic fluids. That's the split across the AAP range AIMS stocks. Match the elastomer to your actual fluid and temperature — the wrong rubber degrades fast.
What sizes do AAP rubber bellows come in?
It depends on the model. The AAP EPDM Table-E bellows runs from 1-1/4" (DN32) up to 24" (DN600) — the widest range in our stock. The Table-E x BS4504 PN16 EPDM version covers 1-1/4"–8" (DN32–DN200), the NBR Table-E covers 2"–6" (DN50–DN150), the NBR ANSI 150 covers 2"–5" (DN50–DN125), and the Table-D RB250D is a fixed 250mm (10"/DN250) size. Check the quick reference table above for the model that matches your flange standard and size.
What flange standard do I need — Table-D, Table-E, ANSI 150 or BS 4504 PN16?
Match whatever's already bolted to your pipework. Table-D and Table-E (AS 4087) are the Australian standard for ductile-iron water-industry pipework — Table-D is the lower-pressure-duty table, Table-E the higher-duty one, and they aren't dimensionally interchangeable with each other. ANSI 150 (ASME B16.5 Class 150) is the US-derived standard common on process plant and pump skids. BS 4504 PN16 is the European 16 bar metric standard, and in many sizes shares Table-E's bolt-hole pattern. A bellows drilled to the wrong standard won't bolt up, regardless of nominal size.
Can a rubber bellows be used to correct pipe misalignment during installation?
No — bellows are designed for movement absorption, not joint repair. Using one to correct gross pipework misalignment goes against standard installation practice and risks premature failure.
Why do rubber bellows need anchor and guide brackets either side of the installation?
Anchor and guide brackets stop pressure thrust from extending the bellows beyond its design movement. On high-pressure or large-bore lines, control rod assemblies may also be needed to limit elongation under fault conditions.
How long do rubber bellows last, and when should I replace one?
Service life depends heavily on operating conditions — temperature, chemical exposure, movement frequency and UV exposure all shorten or extend it, so there's no single figure that applies across every application. Watch for surface cracking, bulging, ply separation or leakage at the end flanges, and plan replacement at the first sign of these during scheduled maintenance rather than after a failure takes the line down.
What temperature range can EPDM and NBR rubber bellows handle?
As a general guide, EPDM handles a wider heat range than NBR and suits hotter water and steam duty, while NBR's range is narrower and centred on oil and fuel service rather than broad heat resistance. Always confirm the exact rating for your specific model with our team before ordering for a high-temperature application.
What brand of rubber bellows does AIMS stock?
AAP is the brand behind every rubber bellows in this range — all five products listed here are supplied by AAP. If you need help matching an AAP bellows to an existing installation or another brand's spec, call our team on (02) 9773 0122 or contact us.