FlexEJ HVAC Team

24hr Shipping
On all stock items ordered.
Mon-Thur by 2pm, 10am Fridays

Design & Manufacturing
Full in-house design & manufacture to EN / ASME / PED.

ISO14001 Accreditation
FlexEJ has an accredited Environmental Management System.

Air & Dirt Separators

FlexEJ Air, Dirt and Air & Dirt Separators can be used in both heating and cooling systems. These robust and cost effective units are manufactured in our UK factory.

Air & Dirt Separation in HVAC Systems

HVAC systems helpAll these products are designed to protect and optimise your heating or cooling system. These products are normally positioned as follows:
Air or Air & Dirt Separator ~ boiler flow lines.
Dirt Separator ~ boiler return lines.
Dosing pots ~ main flow and return.
Low Loss Headers ~ between the boilers and system.

FlexEJ's Air & Dirt Separators

FlexEJ’s manufactures Air, Dirt and combined Air & Dirt Separators in the UK. They can all be bought direct from our web shop on a 24hr dispatch basis (Monday to Thursday). FlexEJ can also manufacture to meet specific client requirements, please get in touch if you do need a custom-designed air & dirt separator built for a specific size or need.

Air Separators Dirt Separators
Air & Dirt Separators Custom fabrication options
Air & Dirt Separators
FlexEJ Air & Dirt Separators

DN50 to DN150


All our chemical air & dirt separators have:
  • Carbon steel body
  • PN16 flanges
  • DN25 drain ball valve
Air Sections – reduce system corrosion by removing air bubbles:
  • Flamco AAV with integral shut-off valve
  • Stainless steel internals
Dirt Sections – reduce dirt and sludge build-up. For further ratings, dimensions and more, please refer the above Range tab, please see our catalogue or range tab above. You can also call/live chat with our expert team.

Shop Now ›

Stock Air & Dirt Separator Finder

Do try our air & dirt separator product finder (below) to check if we have a stock air & dirt separator size and specification that meets your needs. If not then do call us on the usual 01384 881188 or use LIVE CHAT or drop a note or specification to us via our Get A Quote page. We can also help with technicalities, drawings and whatever you need – including flange ends identification although do try our handy Flange Finder if you simply need to identify flange connections needed.

Stock Air & Dirt Separator Finder

Search for FlexEJ air & dirt separators by connection (pipe) size required, intended HVAC use and/or connection hardware (type):

DN32 (1¼″) FlexEJ Air+Dirt Separator
DN32 (1¼″) FlexEJ Air+Dirt Separator
DN40 (1½″) FlexEJ Air+Dirt Separator
DN40 (1½″) FlexEJ Air+Dirt Separator
DN50 (2″) FlexEJ Air+Dirt Separator
DN50 (2″) FlexEJ Air+Dirt Separator

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, the majority of FlexEJ’s current range of Air and Dirt Separators are available from the FlexEJ shop on a same-day despatch basis although our largest Air and Dirt Separators (DN100 to DN150) need to be pallet-delivered and require an extra 2-3 days for delivery. We can also supply Air and Dirt Separators on an ongoing OEM basis and can cater for custom requirements. Please ask for details.

A. Most of our air & dirt separators are available from stock on a 24hr delivery basis. Non-stock separators or custom-manufactured items typically take 7-14 working days, depending on options and quantities required.

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