Three-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 Three-port control valve (3PV) as: ‘An actuated control valve with three ports (usually two inlet and one outlet) which varies the flow through a terminal device by transferring a proportion of the flow through a separate piped bypass…. The majority of three-port valves used in HVAC are mixing valves and as such have two input ports and one output port. A few can be used as diverting valves with one input port and two output ports, but this is rare (except for rotary shoe type valves). As such, there is no ‘diverting’ port when used in most HVAC applications. Instead the mixing valve is installed on the return from a terminal device and as such is described as a ‘mixing valve used in a diverting application.’
It suggests that typical applications include; modulating control of heating or cooling outputs for air handling units, large fan coil units, and plate heat exchangers in constant flow branches.
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles and news
Specifying rendered external wall insulation for fire safety
How to interrogate the evidence provided to the specifier.
The benefits of writing articles for your organisation
How to create a profile for your organisation and publish for free.
No Falls Week. The importance of safe working at height
What to expect and what is on offer to avoid accidents.
Scottish Government action to reach net-zero targets
Retrofit expert group highlight critical actions needed.
A forward thinking, inclusive global community of members.
From engineered product life-spans, to their extension.
Circular economy in the built environment
A brief description from 2021. Where are we now?
Mental Health Awareness Week with ABS
Architects Benevolent Society programme of activity.
CLC publishes domestic retrofit competency framework
Roadmap of Skills for net zero.
May 13-19: Moving more for our mental health.
Understanding is key to conservation.
Open industry engagement survey seeks responses
Institutions and the importance of engagement.
National Retrofit Hub unveils new guide
Digital Building Logbooks and Retrofit: An Introduction.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.