See the range at a glance. We are experts in our field - please get in touch, we love to help.

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FlexEJ Product Range

Pipe Expansion - we manufacture and supply rubber bellows, metal bellows, metal hose, PTFE bellows. Pressure Fabrications - we manufacture pressure vessels, HVAC fabrications, pressure envelopes, packages. From stock, Web Shop, configured, or full manufacture to order. How can we help?

Prefer to talk shop?

Just call us. Or we'll call you.

You can call the team on +44 (0) 1384 881188 or hit the get a quote button and we'll call you back

Pipe Expansion, Pressure Fabrications

Application, design and manufacturing

Bellows & Expansion Joints

DN12 to DN1000
Expansion Joints


Off the shelf and configurable
FlexEJ stocks a wide range of metal and rubber bellows many of which you will find in our Web Shop together with components which we can quickly build up into thousands of different configurations to suit your individual application.

Call, email, chat...we are here to help find the best solution for your application.

Pipe Expansion Joint Manufacture

Metal and Rubber
Pipe Expansion Joint Manufacturing


Manufacture of bespoke joints to over DN3600
FlexEJ has full in-house design, engineering and manufacture capability for metal and rubber expansion joints.

We are PED accredited and will work to your specification and design codes. FlexEJ manufactures for nuclear power plants, pharmaceutical facilities, desalination plants, refineries...all demanding the highest levels of product quality, NDT and documentation.

Pressure Vessels

Pressure Vessel Manufacturing


Manufacture to order
FlexEJ designs and manufactures pressure vessels at our UK fabrication plant, specialising in units with demanding technical and quality requirements in a wide range of metals including Carbon Steel, Stainless Steel, Chrome Moly (CrMo) and Duplex.

We are PED accredited and our welders are qualified under both EN and ASME codes. We offer both build to print and full design with manufacture.

Metal Hose Assemblies

DN6 to DN150
Metal Hose Assemblies


Manufacture to order
FlexEJ manufactures high quality metal hose assemblies using Stainless Steel and Nickel Alloy core tube with external braid as required for the pressure - typically single or double.

Each assembly can be supplied with a very wide range of end fittings to match your requirements along with internal liners or external jackets if required.

Dosing Pots

3.5L to 25L
Dosing Pots


FlexEJ’s own UK manufacture
FlexEJ's dosing pots are manufactured by us in the UK and are available for next day delivery from our Web Shop.

If you require something non-standard please get in touch.

Air & Dirt Separators

DN40 to DN200
FlexEJ Air & Dirt Separator


For use in both heating and cooling systems
FlexEJ's air and dirt separators are manufactured by us in the UK and are available for next day delivery from our Web Shop.

The range covers most requirements but if you need something non-standard please get in touch.

Low Loss Headers - Hydraulic Separators

DN32 to DN150
Low Loss Headers


Compact, value engineered
FlexEJ can manufacture bespoke low loss headers (hydraulic separators) to meet your system needs if our range of standard products is not suitable.

The standard range is all UK made in our factory and available for next day delivery from our Web Shop.


Projects and OEM manufacturing partnerships
Design and Engineering


Full in-house capabilities
FlexEJ has a long history of project execution for large, internationally recognised end-users and contractors. We have robust internal processes to control design, materials and documentation ensuring on time delivery and compliance. Our engineering team can design from scratch to meet your specification or work with existing calculations, concepts or drawings.

We also work with a number of OEMs on a long term basis as their manufacturing partner. We very much welcome the opportunity to develop this type of relationship to bring exceptional added value for our customers.


Our new shop location
FlexEJ Direct Shop


New, expanded, improved shop
FlexEJ's new Web Shop is now available through this web site and offers a much greater range of products all with 24 hour delivery.

HVAC and Elaflex rubber bellows, HVAC metal bellows, Dosing Pots, Air & Dirt Separators, Low Loss Headers plus bolting kits and gaskets all from the Web Shop.

Can't see what you want? Need help?

Call us. Or use Live Chat.

For instant advice. We can custom-design and engineer almost any expansion joint you need for delivery in the UK or worldwide. Call our expert team on +44 (0) 1384 881188. Or email us


Who can you talk to?

Try our sales and customer service team on 01384 881188

They don't bite. And they know what they're talking about. Call the team any time from 8:30am to 3:30pm weekdays, 12:30pm Fridays or use LIVE CHAT if you would prefer a quick text answer. For more complex queries, send us any pro-forma documentation using the get a quote form below or email us

Call Us

Got a quick question?

Use Live Chat. Or call us.

For instant advice use the Live Chat link to message one of the sales team. Or call them direct on +44 (0) 1384 881188

Frequently Asked Questions

Q. What is spring rate?
A. Spring rate is the reaction force of the bellows when it is moved. It is a different force to pressure thrust – both forces act together on the piping. For technical assistance contact us or use our Live Chat facility.
Q. What does bellows ply mean?
A. This is a metal bellows term : ply refers to the number of sheets of metal used in the forming of the bellows, so a 2 ply bellows is made from two sheets of material. A multi ply bellows is generally more flexible that an equivalent single ply bellows. For technical assistance please contact us
Q. What is the difference between a bellows and an expansion joint?
A. In this field, the terminology can be confusing, often with no universally accepted meaning. We tend to use the following definitions but the terms “bellows” and “expansion joint” are typically considered as interchangeable: > Expansion Joint – an expansion joint is a complete unit with metal bellows or rubber bellows and end fittings, plus, optionally, liner, cover and external hardware. Other terms used : compensator, flexible connector. > Rubber Bellows – the flexible element within a rubber expansion joint > Metal Bellows – the flexible element within a metal expansion joint > Liner – The liner fits within the expansion joint under the metal bellows or rubber bellows to prevent the flowing media directly impinging on the bellows. This this reduces flow disturbance and allows the temperature of the bellows to be controlled in the design. For technical assistance please contact us or use our Live Chat facility.
Q. What are tie rods or a tied metal or rubber bellows?
A. A tie rod is a simple pressure thrust restraint. It will allow reasonable lateral movement but not axial extension; it can allow axial compression if the pressure thrust is overcome by the piping movement. See the movements and pressure thrust FAQs for definitions. For technical assistance please contact us or use our Live Chat facility.
Q. What is pressure thrust or force?
A. All expansion joints exert a force, pushing the pipe ends apart – pressure thrust – which is proportional to the operating pressure and diameter of the bellows. If the expansion joint is unrestrained the piping system must withstand the force, or, alternatively, the expansion joint may have restraints built in to constrain the pressure thrust force. For instance types, tie rod, hinge or gimbal. For technical assistance please contact us or use our Live Chat facility.
Q. What information do I need to design or select a rubber bellows or metal expansion joint?
A. To design or select a rubber bellows or metal expansion joint we need to know: nominal bore, end type, service, temperature, pressure and required movements. You may also specify in addition your requirements for external hardware – tie rods, hinges, gimbals – internal liner, external cover and instrumentation. Material selections should also be specified to suit the service and associated system piping. For technical assistance please contact us or use our Live Chat facility.
Q. What is EJMA?
A. The EJMA is the Expansion Joints Manufacturers Association. Their bellows calculation method is most frequently used for metal bellows expansion joint design. EJMA does not cover rubber bellows or metal hose design. For technical assistance please contact us or use the LIVE CHAT link on this page.

Please visit our full FAQ page to see all our frequently asked questions.

Can't quite find the right bellow?

Try the FlexEJ Bellows Finder

Or call our expert team on +44 (0) 1384 881188

Got a quick question?

Use Live Chat. Or call us.

For instant advice use the Live Chat link to message one of the sales team. Or call them direct on +44 (0) 1384 881188

Get A Quote

Please complete the short form here and we'll get back to you within 24hrs Monday to Friday (quicker if marked urgent).

Alternatively, you can also call our expert team directly on +44 (0) 1384 881 118 from 8:30AM to 4:30PM weekdays (12:30PM Fridays), who will be only too pleased to talk through your requirements and technical queries over the phone.

Visitors are also welcome Monday to Friday although please get in touch beforehand to let us know you're coming.

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    Industry experience

    FLEXEJ Ltd was formed in 2002 by two professional engineers who brought together an already highly respected design capability with business and commercial skills gained in large multinational companies.
    • Our focus has always been on application and design – helping our customers find the best value solution.
    • We have a strong engineering and manufacturing team with experience in petrochemicals, refining, nuclear, desalination though to HVAC.
    • The team is also very familiar with meeting complex requirements for documentation, in process NDT and test on projects. We have supplied many large end-users such as EDF, Exxon, Shell, Reliance & QatarGas working with major contractors such as JGC, Foster Wheeler & Technip.
    FlexEJ Industry Experience