Industriearmaturen Rubber Expansion Joints

Rubber Expansion Joint for Pipelines – Compensators in Steel, Stainless Steel and Ductile Iron

Fergo supplies rubber expansion joints (also called rubber compensators or pipeline expansion joints) to absorb thermal expansion, vibration, structure-borne noise and installation misalignment. Available as single-sphere or twin-sphere rubber expansion joint, as rubber-metal pipe connector or as threaded expansion joint. Bellows in EPDM or NBR, flanges in galvanised steel, stainless steel SS316 or galvanised ductile iron, from DN15 to DN500, PN10/PN16, face-to-face lengths 130 mm, 150 mm or 200 mm, optionally with vacuum support ring.

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Design

NBR & EPDM 2+

Material Bellow

Face to Face length Options

70mm, 130mm, 150mm, 200mm

Rubber expansion joint type OG150

Sizes: DN25 – DN600

Flange connection: PN10, PN16

Face-to-face: 130 mm, 152 mm, 203 mm

Bellows: EPDM, Nitrile/CR

Flange material: Galvanized steel, stainless steel
Rubber expansion joint type OG130

Sizes: DN25 – DN600

Flange connection: PN10, PN16

Face-to-face: 130 mm, 152 mm, 203 mm

Bellows: EPDM, Nitrile/CR

Flange material: Galvanized steel, stainless steel
OG111 Threaded rubber expansion joint

Sizes: 1/2", 3/4", 1", 1 1/4", 1 1/2", 2", 2 1/2", 3"

Connection: Internal Thread

Pressure range: PN10/16

Bellows: EPDM

Thread: Internal thread according to BSPP

Product Overview

Expansion Joints & Compensators – Rubber Expansion Joint and Pipeline Expansion Joint from DN15 to DN500, PN10/PN16

An expansion joint (also called rubber compensator or pipeline expansion joint) is a flexible pipeline element that absorbs thermal expansion, vibration and installation misalignment. Without a compensator in the pipeline, mechanical stresses arise that cause pipe fractures, leaks at pumps and valves, and premature wear of pipe supports. The rubber expansion joint consists of a fabric-reinforced elastomer bellows (EPDM or NBR) between two connection flanges. The elastic bellows simultaneously absorbs axial, lateral and angular movements as well as structure-borne noise. Construction follows DIN 4809 for rubber expansion joints in pipelines and EN 1092-1 for flanged connections.

Fergo offers four series. The OG130 series is the single-sphere rubber expansion joint with 130 mm face-to-face length – the right choice for standard HVAC, drinking water and process applications from DN32 to DN300 with galvanised steel flanges. The OG150 series has a face-to-face length of 150 mm or 200 mm and is available with flanges in galvanised steel or stainless steel SS316 – the right choice for chemical processing, food and beverage and aggressive media. The OG111 series is the twin-sphere threaded rubber expansion joint with BSPP female thread and ductile iron flanges for drinking water and HVAC installations from 1 inch to 3 inch. The SD100 series is the rubber-metal pipe connector with metal connection stubs and EPDM bellows – the right choice for reliable connection between dissimilar pipeline materials.

Typical applications: HVAC (heating, ventilation, air conditioning), drinking water supply, wastewater, chemical processing, petrochemicals, power generation, shipbuilding, pump connections, compressor connections, plant engineering and process industry. A compensator upstream of a ball valve or butterfly valve installation significantly reduces load on the fitting, noise generation and maintenance cost.

Expansion Joint Categories at Fergo

01 Flanged Rubber Expansion Joint OG130 / OG150 – Single-Sphere

The flanged rubber expansion joint of the OG130 and OG150 series is the standard rubber compensator for pipelines with flanged connection PN10/PN16 per EN 1092-1. Nominal sizes from DN32 to DN300. Face-to-face length 130 mm (OG130) or 150 mm/200 mm (OG150). Bellows in EPDM (standard, red-marked) or NBR (yellow-marked), fabric-reinforced with nylon cord. Flanges in galvanised steel (standard) or stainless steel SS316. The compensator is clamped between two existing pipeline flanges and is directly interchangeable. Working pressure up to 16 bar, temperature –30 °C to +110 °C.

02 Twin-Sphere Rubber Expansion Joint OG111 – Threaded

The twin-sphere rubber expansion joint (double-sphere) of the OG111 series features BSPP female thread and galvanised ductile iron flanges. Available from 1 inch (DN25) to 3 inch (DN80). Face-to-face length 203–240 mm. The twin-sphere (double-bellows) design doubles the movement absorption compared to the single-sphere rubber expansion joint and is the right choice for drinking water (EPDM), HVAC systems and installations with elevated vibration load such as pump connections and compressor connections.

03 Rubber-Metal Pipe Connector SD100

The rubber-metal pipe connector of the SD100 series firmly bonds a metal connection stub to an EPDM bellows – the right choice for a durable connection between dissimilar pipeline materials and for applications with high axial pre-tension. The SD100 compensates thermal expansion, vibration and settlements and is typically used for pump connections in water treatment plants, sewage plants and fire protection systems.

04 Vacuum Rubber Expansion Joint with Support Ring

The vacuum rubber expansion joint is a version of the OG130 and OG150 series with a stainless steel SS316 vacuum support ring inside the bellows. The support ring prevents bellows collapse in sub-atmospheric applications (vacuum down to –0.8 bar). Movement absorption is reduced by approx. 50 % versus the standard version. Typical applications: pump suction lines, vacuum systems, pneumatic solids conveying and installations with alternating pressure conditions.

05 Stainless Steel Rubber Expansion Joint SS316 – Flanged

The stainless steel rubber expansion joint with SS316 (1.4408) flanges is the right choice for chemical processing, pharmaceuticals, food and beverage, drinking water treatment, seawater applications and all corrosive media. SS316 flanges prevent rust and corrosion issues that would occur with galvanised steel flanges in aggressive environments. Available for the OG130 and OG150 series from DN32 to DN300 with EPDM or NBR bellows.

06 Galvanised Steel Rubber Expansion Joint – the economical standard

The galvanised steel rubber expansion joint is the economical standard solution for HVAC, drinking water, wastewater, cooling water, heating systems and general process applications. The galvanising reliably protects the steel flanges against corrosion in normal operating environments. Available for the OG130 and OG150 series from DN32 to DN300 with EPDM or NBR bellows, face-to-face length 130 mm, 150 mm or 200 mm.

Materials in Detail

Materials of the Expansion Joints – Bellows and Flanges

1. Bellows EPDM (Ethylene-Propylene-Diene Rubber)

Application: drinking water (DVGW-capable), cold and hot water, HVAC, heating systems, condensate, diluted acids and alkalis, glycol-based brake fluids, ozone-loaded environments.
Temperature: –30 °C to +110 °C.
Colour code: red.
Advantages: excellent ozone, UV, weathering and ageing resistance, higher temperature capability than NBR, drinking-water approved.
Limitations: not suited for mineral oils, greases, fuels and aromatic hydrocarbons.

2. Bellows NBR (Nitrile-Butadiene Rubber)

Application: mineral oils, hydraulic oils, fuels (diesel, petrol), greases, heating oil, biogas, natural gas, oil-laden media and compressed air with oil content.
Temperature: –20 °C to +90 °C.
Colour code: yellow.
Advantages: excellent resistance to aliphatic hydrocarbons, oils and fuels.
Limitations: not resistant to ozone, UV, aromatic hydrocarbons and strongly oxidising media.

3. Bellows Reinforcement – Nylon Cord

Construction: multi-layer nylon cord inlay in the elastomer bellows, fabric-reinforced for pressure resistance and dimensional stability.
Advantages: absorbs the axial tensile and compressive forces without impairing the elasticity of the elastomer, prevents bulging under internal pressure, secures the PN10/PN16 pressure rating.

4. Galvanised Steel Flanges

Application: standard for HVAC, drinking water, wastewater, cooling water, heating systems.
Material: S235JR (1.0038) with electroplated or hot-dip galvanising.
Advantages: cost-effective, sufficient corrosion resistance in normal operating environments, high flange rigidity.
Limitations: not suited for aggressive chemicals, seawater and applications with frequent moisture exposure without additional corrosion protection.

5. Stainless Steel Flanges SS316 (1.4408 / 1.4404)

Application: chemical processing, pharmaceuticals, food and beverage, seawater, drinking water (recommended per DIN 4809), aggressive process media.
Advantages: full corrosion resistance, hygienically safe, significantly longer service life than galvanised steel in aggressive media.
Limitations: higher unit cost.

6. Galvanised Ductile Iron Flanges (EN-GJS-400-15)

Application: OG111 series (threaded rubber expansion joint) with BSPP female thread.
Advantages: high mechanical strength, good thread machinability, compact form.
Limitations: limited nominal sizes (only OG111 series, 1 inch to 3 inch).

7. Vacuum Support Ring – Stainless Steel SS316

Construction: ring-shaped reinforcement in stainless steel SS316 inside the bellows to prevent collapse under sub-atmospheric pressure.
Advantages: enables rubber expansion joint use in vacuum and suction lines.
Limitations: reduces movement absorption by approx. 50 %.

Movement Types & Installation Guidelines – Technical Design of the Compensator

Movement Absorption, Technical Specifications and Installation Guidelines

A compensator in the pipeline simultaneously absorbs three different movement types: axial movement (extension/compression along the pipe axis), lateral movement (offset perpendicular to the pipe axis) and angular movement (angular rotation at a point). Correct selection and installation determine the service life and functional safety of the rubber expansion joint.

Axial Movement (Thermal Expansion)

The rubber expansion joint compensates the thermal length change of a pipeline section. Rule of thumb: steel pipe expands approx. 1.2 mm per metre pipe length per 100 °C temperature rise. Single-sphere series OG130 and OG150 typically absorb ±8 to ±12 mm axially (positive compression, negative extension). Twin-sphere series OG111 doubles these values to ±16 to ±25 mm. For larger axial movements, connect compensators in series or introduce fixed points in the pipeline.

Lateral Movement (Transverse Offset)

The rubber expansion joint compensates lateral offset between adjacent pipeline sections. Single-sphere OG130/OG150 typically absorb ±5 to ±8 mm laterally, twin-sphere OG111 ±10 to ±15 mm. Lateral movements typically arise from foundation settlement, vibrations from pumps and compressors, and thermal expansion in adjacent pipeline sections.

Angular Movement (Angular Rotation)

The rubber expansion joint compensates angular rotation of typically ±15° for single-sphere series and ±25° for twin-sphere series. Angular movements occur particularly at pipe bends and with larger pipeline radii.

Technical Specifications of the Fergo Series

OG130: face-to-face 130 mm, DN32–DN300, PN16, ±10 mm axial, ±6 mm lateral, ±15° angular, –30 °C to +110 °C.
OG150: face-to-face 150 mm (up to DN150) or 200 mm (DN200–DN300), PN16, ±12 mm axial, ±8 mm lateral, ±15° angular, –30 °C to +110 °C.
OG111: twin-sphere, face-to-face 203–240 mm, DN25–DN80 (1–3 inch), PN16, ±22 mm axial, ±12 mm lateral, ±25° angular, –10 °C to +110 °C.
SD100: rubber-metal pipe connector, EPDM bellows with metal connection stubs.

Installation Guidelines – 8 Rules for Correct Assembly

1. Align pipeline: Before installation, the two pipeline flanges to be connected must be aligned coaxially. The rubber expansion joint is not an assembly aid for misaligned pipes.
2. Observe face-to-face length: The distance between the two pipe flanges must exactly match the nominal face-to-face length (130 mm, 150 mm or 200 mm). Over- or under-tensioning in the new state drastically reduces service life.
3. Set fixed points: Fixed points are required before and after the compensator in the pipeline to absorb the axial reaction forces. Without fixed points, the pipeline shifts instead of the bellows absorbing the movement.
4. Maintain clearance from bends: Maintain at least 4× DN clearance from downstream bends to avoid turbulence at the bellows.
5. Tighten screws crosswise: Tighten flange screws crosswise with the manufacturer’s specified torque (typically 20–60 Nm depending on nominal size). Over-tightening crushes the bellows, under-tightening causes leaks.
6. No welding nearby: When welding on the pipeline, dismantle the compensator or protect it with a heat shield. EPDM and NBR lose their elasticity above +150 °C.
7. Vacuum support ring for sub-atmospheric duty: For vacuum or sub-atmospheric applications (below 0 bar), the version with vacuum support ring in stainless steel SS316 is mandatory to prevent bellows collapse.
8. Regular inspection: Inspect the bellows at least once yearly for cracks, bulges, abrasion and ozone ageing. Elastomer compensators have a typical service life of 8–12 years; ozone or UV exposure may shorten this.

Selection Guide – Which Rubber Expansion Joint?

Standard HVAC and drinking water with EPDM: OG130 or OG150 with galvanised steel flanges.
Chemistry and seawater with EPDM: OG130 or OG150 with stainless steel SS316 flanges.
Oil, fuel and biogas: OG130 or OG150 with NBR bellows.
Pump/compressor connection with high vibration: twin-sphere OG111 or rubber-metal pipe connector SD100.
Vacuum and suction lines: OG130 or OG150 with vacuum support ring.
Drinking water installation 1–3 inch with thread: OG111 twin-sphere.

Fergo expansion joints comply with the key European standards for rubber expansion joints in pipelines. Construction follows DIN 4809 for rubber expansion joints with elastomer bellows and fabric-reinforced inlays. Flanged connections comply with EN 1092-1 form B1 (steel and stainless steel) and EN 1092-2 (ductile iron). Threaded connections follow ISO 228-1 (BSPP). Pressure testing follows EN 12266-1. PED 2014/68/EU is covered for applicable models. EPDM bellows variants are drinking-water approved per KTW recommendation and DVGW test (on request).

Factory certificates, 3D models and technical datasheets are available on the Fergo certificates page. EPDM or NBR bellows compatibility with specific media can be checked via the chemical resistance tool.

Fergo offers over 500 rubber expansion joint, pipeline expansion joint and rubber-metal pipe connector references from stock in Neuss, Germany. Shipping covers the UK, Europe and worldwide. Standard delivery via DHL is 2–7 working days. All terms are detailed on the shipping and payment terms page.

For projects requiring a compensator with special face-to-face length, PN25 version, PTFE bellows (chemistry), metal bellows (high temperature) or custom flange design, Fergo develops customised solutions.