Pressure Relief Dampers
Strong, durable and effective
Our multi-leaf pressure relief damper units – Type MLD – swing open when the air pressure exceeds a certain limit to allow air to be discharged.
The pressure relief dampers consist of a single set of horizontal light gauge plastic flaps mounted on stainless steel axles, which pivot about their top edge.
Manufactured in the UK, our pressure relief dampers combine the strength of steel with the durability of plastic.


Benefits of FNW pressure relief dampers
- Range of sizes – Type MLD is produced in standard sizes of 50mm increments from 150 x 150mm up to 1000 x 1000mm inclusive
- Bespoke products available – dampers can be produced in any intermediate size of height or length.
- Different colours available – black or white
- Corrosion protection – the damper is manufactured in zinc coated steel and polyester powder coated prior to assembly. Also available in stainless steel for enhanced corrosion protection
- Accommodating – dampers can be supplied without fixing flanges, with the damper mounted in a channel frame for securing inside the duct or opening
- Universal – dampers may be fitted in a unit with any return air grille or louvre with the grille casing being extended to accommodate the pivoting flaps
- Flexible – if dampers are fitted within an internal wall or partition, the spigot depth can be reduced and a matching rear loose flange provided for fitting to the rear of the opening
- Adaptable for external walls – if fitted to an external wall a cowl or external louvre should be fitted to minimise the effects of wind pressure.
