Four-port control valve
Selection of Control Valves in Variable Flow Systems (BG 51/2014) written by Chris Parsloe and published by BSRIA in June 2014, defines a four-port control valve (4PV) An actuated control valve with four ports (two inlet and two outlet) which varies flow through a terminal device by diverting a proportion of the flow through an integral “restricted” bypass avoiding the need for a separate piped bypass… Four-port valves are always designed as mixing valves but are commonly used in diverting applications.
It suggests that typical applications include; modulating control of heating and cooling, outputs from small fan coil units or chilled beams (typically up to a 20 mm pipe size) in constant flow branches.
--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.