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Industriearmaturen Rubber Expansion Joints

Rubber Expansion Joints DN20 to DN500 Ex Stock

Rubber expansion joints and pipe connectors with EPDM or NBR bellows, galvanised or stainless steel flanges, DN20 to DN500, PN10 and PN16, three face-to-face lengths.

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Rubber Expansion Joints
  • Rubber expansion joint type OG150

    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

    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

Product Overview

Rubber Expansion Joints: Movement, Vibration and Thermal Expansion Control

A rubber expansion joint — often called a rubber compensator — absorbs axial, lateral and angular movement in a pipeline. In addition to that mechanical function, the elastic bellow dampens pump vibration, cushions pressure surges and compensates for thermal expansion. As a result, the expansion joint protects pumps, flow meters, flanged valves and downstream equipment from stress cracks, flange leakage and premature wear.

Fergo supplies the OG series in two face-to-face lengths — OG130 at 130 mm and OG150 at 150 mm and 200 mm. Nominal sizes reach from DN20 up to DN500 at PN10 and PN16. Flange drilling follows DIN EN 1092-1. Bellows are made of EPDM (red code, nylon-reinforced) or NBR, both nylon-reinforced for tensile strength. Flanges come in galvanised steel or stainless steel, with an optional vacuum support ring in SS316 for negative-pressure and suction service.

Expansion joints belong in pump discharge lines, HVAC and district heating circuits, chemical and process pipework, water and wastewater plants, ventilation ducts and industrial cooling systems. They pair naturally with a downstream ball check valve to protect against water hammer when a pump shuts down. Do not confuse the compensator with the rubber-metal pipe connector: the connector at 70 mm face-to-face length only isolates vibration and offers no movement compensation.

Subcategories: Expansion Joints by Design

01 Rubber Compensators (OG130 and OG150)

The rubber compensator is the workhorse for combined movement and vibration duty. The OG130 at 130 mm face-to-face length covers DN20 through DN300. The OG150 at 150 mm or 200 mm face-to-face length reaches DN300 up to DN500. Bellows are made of EPDM (red colour code, nylon-reinforced) or NBR, and the two integrated flanges come in galvanised steel or stainless steel. Standard pressure ratings are PN10 and PN16, with a maximum operating temperature of +110 °C for EPDM depending on the working pressure. This design absorbs axial compression, elongation, lateral offset and angular movement in a single component.

For suction, vacuum and negative-pressure service, Fergo supplies the same OG150 with a vacuum support ring in stainless steel SS316. The support ring keeps the bellow from collapsing under negative pressure. It reduces the movement capacity by approximately 50 percent, so the trade-off should be considered during sizing. Vacuum-supported versions are stocked from DN200 to DN300 and available on request up to DN500.

02 Rubber-Metal Pipe Connectors

The rubber-metal pipe connector is a short, compact vibration decoupler at a face-to-face length of only 70 mm. Body in EPDM, flanges in zinc-plated mild steel (RST 37-2), maximum working pressure 10 bar. Available from DN20 up to DN150, with larger sizes on request. Important distinction: this product isolates vibration only — it has no movement capacity and therefore cannot replace a rubber expansion joint where axial, lateral or angular compensation is required.

Materials in Detail: Specifying the Right Expansion Joint

Bellow Materials

1. EPDM (Ethylene Propylene Diene Monomer), Nylon-Reinforced

  • Application: drinking water, hot water, HVAC circuits, dilute acids and alkalis, wastewater; standard bellow of the OG series (red colour code)
  • Temperature: up to +110 °C (depending on operating pressure)
  • Advantages: excellent ozone and ageing resistance, wide temperature window, nylon reinforcement adds tensile strength, WRAS/drinking-water versions available
  • Limitations: not compatible with mineral oils, hydrocarbons or petroleum products

2. NBR (Nitrile Butadiene Rubber), Nylon-Reinforced

  • Application: mineral oils, hydraulic fluids, hydrocarbon-loaded media, oil-water mixtures, wastewater with organic content
  • Temperature: up to +90 °C (depending on operating pressure)
  • Advantages: outstanding oil and grease resistance, nylon reinforcement raises pressure rating, economical
  • Limitations: not ozone-resistant, unsuitable for hot water above +90 °C or steam

3. PTFE-Lined Bellow (on request)

  • Application: aggressive acids, alkalis and solvents in the chemical industry; the bellow is EPDM with an internal PTFE liner
  • Temperature: up to +150 °C
  • Advantages: near-universal chemical resistance on the wetted surface combined with the elasticity of the EPDM carrier, FDA-compliant on the wetted side
  • Limitations: movement capacity slightly reduced compared to plain EPDM; special order with surcharge

4. Hypalon-Coated Bellow (on request)

  • Application: chemical service with oxidising media, ozone, chlorine and chlorine dioxide; typically paired with stainless steel flanges
  • Temperature: up to +100 °C
  • Advantages: excellent chemical and weathering resistance, especially against oxidisers where EPDM and NBR reach their limit
  • Limitations: special order with surcharge; extended lead time

Flanges and Reinforcement

1. Flanges Galvanised Steel (RST 37-2)

  • Application: standard flanges of the OG series and rubber-metal pipe connectors for water, wastewater, HVAC and general utility duty
  • Temperature: matched to the bellow material
  • Advantages: high mechanical strength, wide-range corrosion protection through the zinc layer, economical for stock production, EN 1092-1 flange geometry
  • Limitations: not suitable for aggressive chemicals or heavily chloride-loaded media

2. Flanges Stainless Steel

  • Application: chemical and food service, seawater, chloride-loaded media, wherever the process must not contact carbon steel
  • Temperature: matched to the bellow material
  • Advantages: high corrosion resistance, hygienic surface, mandatory pairing with PTFE-lined or Hypalon-coated bellows
  • Limitations: higher material cost than galvanised steel

3. Vacuum Support Ring SS316

  • Application: suction lines, vacuum applications, negative-pressure service where the bellow would otherwise collapse
  • Temperature: matched to the bellow material
  • Advantages: SS316 support ring keeps the flow path fully open under negative pressure, retrofitable to standard OG150 assemblies
  • Limitations: reduces the movement capacity of the bellow by approximately 50 percent

Certificates & Standards for Expansion Joints

Fergo rubber expansion joints comply with the Pressure Equipment Directive 2014/68/EU and carry the CE mark. Flange dimensions follow DIN EN 1092-1 for PN10 and PN16, so the compensator drops straight onto counter-flanges of your flanged ball valves or flanged butterfly valves. WRAS-approved EPDM bellows are available on request for drinking-water installations.

Inspection documents to EN 10204 — type 2.2 works certificate or type 3.1 inspection certificate — are supplied on request. A full overview of all certificates is published on the Fergo certificate page. You can verify bellow compatibility with your medium beforehand using the Fergo resistance check. Suitable flange gaskets in aramid fibre or graphite are also kept in stock.

Delivery & Availability

Fergo holds more than 25,000 industrial valves in stock, including a wide OG series programme in the three standard face-to-face lengths and both flange materials. Standard nominal sizes are picked the same working day, so delivery follows within two to seven working days. 3D CAD STEP models and data sheets for every assembly are available for direct integration into your engineering design.

Fergo ships across Europe — including the United Kingdom, the Nordic countries and all other EU member states. Smaller sizes travel by parcel service, whereas large-bore compensators and consolidated shipments go by forwarding agent. You will find shipping costs, payment options and express terms on the shipping and payment terms page. For PTFE-lined bellows, Hypalon coating, vacuum support rings above DN300 or DN500 sizes, please contact us through the customised solutions section.