Spring actuator
Guide to Controls (BG 83/2023) written by John Marrow and published by BSRIA in June 2023, states in relation to spring actuators or power fail actuators: ‘Sometimes, a control valve needs to fully close or open quickly during a high temperature or power failure condition. In this case the actuator is provided with a spring or power return feature. On excess temperature a separate high limit device, such as a thermostat, can be used to break the power supply. This releases a clutch within the actuator which takes control away from the normal sensor. The spring will quickly close the valve or, in some applications, open it to relieve the high temperature. The same would also happen in an unmanaged electrical supply failure.’
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles and news
A landmark moment for postmodern heritage.
A safe energy transition – ECA launches a new Charter
Practical policy actions to speed up low carbon adoption while maintaining installation safety and competency.
Frank Duffy: Researcher and Practitioner
Reflections on achievements and relevance to the wider research and practice communities.
The 2026 Compliance Landscape: Fire doors
Why 'Business as Usual' is a Liability.
Cutting construction carbon footprint by caring for soil
Is construction neglecting one of the planet’s most powerful carbon stores and one of our greatest natural climate allies.
ARCHITECTURE: How's it progressing?
Archiblogger posing questions of a historical and contextual nature.
The roofscape of Hampstead Garden Suburb
Residents, architects and roofers need to understand detailing.
Homes, landlords. tenants and the new housing standards
What will it all mean?
The Architectural Technology podcast: Where it's AT
Catch-up on the latest episodes.
Edmundson Apprentice of the Year award 2026
Entries now open for this Electrical Contractors' Association award.
Traditional blue-grey slate from one of the oldest and largest UK slate quarries down in Cornwall.
There are plenty of sources with the potential to be redeveloped.
Change of use legislation breaths new life into buildings
A run down on Class MA of the General Permitted Development Order.
Solar generation in the historic environment
Success requires understanding each site in detail.