HIGH-TEMPERATURE HVAC METAL Bellows
For long term high temperature exposure
24hr Shipping
On all stock items ordered.
Mon-Thur by 12:30pm, 9:30am Fridays
Design & Manufacturing
Full in-house design & manufacture to EN / ASME / PED.
ISO14001 Accreditation
FlexEJ has an accredited Environmental Management System.
HVAC Metal Bellows
Metal bellows specifically designed for HVAC applications in a range of styles to suit your piping:
PRODUCT GUIDES
HVAC METAL BELLOWS
WHAT IS AN HVAC METAL BELLOW?
HIGH-TEMPERATURE DESIGN WITH FLANGED, COPPER OR UNION ENDS…
Design
Extensive range of metal bellows suitable for a wide range of HVAC services.
Performance
High quality bellows manufactured in 316 stainless steel.
Application
Potable water, heating water, steam.
WEB SHOP
Available online with next day delivery from our web shop.
COPPER END HVAC METAL BELLOWS
| SIZE | LENGTH | COPPER PIPE SIZE | PRESSURE RATING | MOVEMENT | IN SHOP |
|---|---|---|---|---|---|
| DN12-½″ | 220 | 15 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
| DN20-¾″ | 230 | 22 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
| DN25-1″ | 235 | 28 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
| DN32-1¼″ | 245 | 35 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
| DN40-1½″ | 250 | 42 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
| DN50-2″ | 250 | 54 | 6 Barg @ 90 ºC | Axial +0/-25 mm | Yes |
UNION END HVAC METAL BELLOWS
| SIZE | LENGTH | PRESSURE RATING | MOVEMENT | IN SHOP |
|---|---|---|---|---|
| DN12-½″ | 181 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
| DN20-¾″ | 187 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
| DN25-1″ | 191 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
| DN32-1¼″ | 207 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
| DN40-1½″ | 215 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
| DN50-2″ | 229 | 6 Barg @ 150 ºC | Axial +0/-25 mm | Yes |
HVAC AXIAL METAL BELLOWS
| SIZE | LENGTH | PRESSURE RATING | MOVEMENT | IN SHOP |
|---|---|---|---|---|
| DN50-2″ | 130 | 10 Barg @ 110 ºC | Axial +/- 10 mm | Yes |
| DN65-2½″ | 130 | 10 Barg @ 110 ºC | Axial +/- 13 mm | Yes |
| DN80-3″ | 130 | 10 Barg @ 110 ºC | Axial +/- 14 mm | Yes |
| DN100-4″ | 150 | 10 Barg @ 110 ºC | Axial +/- 15 mm | Yes |
| DN150-6″ | 150 | 10 Barg @ 110 ºC | Axial +/- 19 mm | Yes |
HVAC PUMP METAL BELLOWS
How to specify a metal expansion joint
We design and manufacture metal expansion joints so you are not restricted to our range of standard products, some of which are available in our web shop. For simpler applications a standard product may be entirely suitable but if not we will design to meet your exact requirements.
Metal bellows have a defined fatigue life based on movement cycles. Understanding the movements, if they are concurrent or not and the realistic number of times the movements can occur is fundamental to metal bellows design.
Metal bellows work well up to around 500ºC, above that we use insulation to control the actual bellows metal temperature if the media is above this temperature. Pressure and temperature must be known to select a metal expansion joint.
The most common material used for metal bellows is Stainless Steel – 304, 321, 316 – and for more demanding applications Nickel Alloys – 625, 800, 825. Corrosion is the most likely failure mode for the bellows itself so the correct material selection is important.
Our standard ranges have set lengths for each diameter / movement range but we can design to meet your exact requirements. Making the bellows longer will increase the available movement. Most commonly a flange, we can provide to any specification, or pipe weld ends. Our HVAC standard product is available with BSP Union ends and Copper Pipe ends. If you are uncertain about what flange type you already have installed our Flange Finder will help you identify it.
Call our expert team on +44 (0) 1384 881188 or email us at sales@flexej.co.uk or use Live Chat on this web site – we are here to help, please get in touch.FlexEJ’s HVAC Metal Bellows
FlexEJ’s has the following ranges of HVAC Metal Bellows available:
HVAC COPPER END METAL BELLOWS
EN1057 Table X copper ends
FlexEJ’s copper ended bellows are WRAS approved for drinking water. Minimum length designs for axial compression with 316 stainless steel bellows rated at 6 Barg @ 90°C
HVAC UNION END METAL BELLOWS
EN10242 Female union ends
Union ended bellows. Minimum length designs for axial compression with 316 stainless steel bellows rated at 6 Barg @ 150°C
AXIAL METAL BELLOWS
EJMA calculated punch formed bellows
FlexEJ’s Short Axial range offer moderate axial movements and are consequently shorter overall. Stainless Steel 321 bellows, designed to EJMA, manufactured by punch forming. Minimum overall length design with PN16 carbon steel flanges. These expansion joints are rated for applications up to 10 Barg @ 110°C.
HVAC PUMP BELLOWS
EJMA calculated punch formed bellows
FlexEJ’s Pump range offer small lateral movements suited to pump alignment and vibration applications. Available as tied and untied. Stainless Steel 321 bellows, designed to EJMA, manufactured by punch forming. Minimum overall length design with PN16 carbon steel flanges. These expansion joints are rated for applications up to 10 Barg @ 110°C.
HVAC Metal Bellows Finders and Calculators
We have a couple of easy to use tools and calculators to help you resource the best HVAC metal bellows from our next-day delivery stock items. Our Thermal Expansion Calculator for Piping helps you estimate the increase in length of a pipe run with temperature.
Our Advanced Bellows Finder is a quick way to navigate our the full range of on-line metal and rubber expansion bellows and joints – with 24hr delivery across the UK. With just a few choices you can arrive at the appropriate selection – criteria include pipe size, type, media compatibility, installation length, pressure rating, pipe connection type, conformance and movement axial, lateral and angular. All the products are in the online store with 24hr shipping as standard. If you’re not sure what flange you need, our handy Flange Finder should also be useful.Stock HVAC Metal Bellows Finder
Do search for HVAC Metal expansion joints by pipe size, intended media and/or connection hardware to see FlexEJ’s stock of next-day deliverable metal bellows options but don’t hesitate to call us on 01384 881188 or email us for more bespoke options, sizes and restraint configurations or technical advice.
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 sales@flexej.co.uk
HVAC & Industrial Bellows Comparison Charts
What is the best pump or axial bellow for your application? Four potential alternatives to consider:
Stainless steel
Bellows Material and Design
Is the bellows Stainless Steel and calculated to EJMA?
Flow Liner
Flow Liner
Is a Flow Liner included?
Any flange / weld end
Any Flange or Weld End
Is any common flange type or pipe weld end available?
Range of length
Range of lengths
Can an overall length greater than minimum be specified?
Rating barg/°C
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 sales@flexej.co.uk
Frequently Asked Questions
A. Our Flange Finder contains details for many common flanges. Typically, to be able to make the identification you need to know the bore size or outside diameter and number of bolts. For technical assistance contact us or use our Live Chat facility.
A. Yes, FlexEJ has full design capability for engineered metal expansion joints and can work to any recognised standard – typically EJMA, B31.3/Appendix X, EN14917 plus PED and/or other customer specifications. Engineered rubber expansion joints are typically designed to meet the FSA guidelines plus PED and/or other customer specifications For technical assistance please contact us or use the Live Help link on this page.
A. Yes, if you have the details we can normally offer an equivalent, our FAQ here gives the information we will need for a full selection. For technical assistance please contact us or use the Live Chat link on this page.
A. To identify an existing expansion joint we need to know: nominal bore, overall length and flange type plus service, temperature, pressure and required movement if known. Try our Flange Finder to help identify the flange and you can send us a picture of the existing part using the Contact us form. For technical assistance please contact us or use the LIVE CHAT link on this page.
A. Yes, our MRCA copper ended metal expansion joints also have WRAS approval. We laso have DWI approval for stainless steel expansion joints. For technical assistance please contact us or use the Live Chat link on this page.












