Three-way valve (definition)

Three-way valve — is a device used in heating, ventilation, air conditioning and water supply systems to regulate the flow of liquid or gas between three different points or directions. It consists of a body with three openings and an internal crosspiece (ball or switching element) that allows the flow to be directed depending on the position.

Three-way valves are widely used for mixing or switching coolant flows, which allows you to regulate the temperature, pressure or distribution of liquid or gas in systems with several circuits or zones. The main functions include balancing the boiler operation by mixing water into the return pipe of the heating circuit, can perform the functions of regulating "warm floors" or in hot water supply systems without more complex structural elements of hydraulic isolation, and also regulates the temperature of the water supply to the radiators. In premium systems, three-way valves are used to protect boilers from low-temperature corrosion.

Three-way valve: design features

The valve is designed for external control of a microcontroller or thermostatic head with an ambient air temperature sensor (built-in or remote). Its main function is to mix colder water and stabilize the temperature. The mixing valve with a drive works in combination with temperature sensors; when the temperature is exceeded, the valve with cold water opens, and mixing occurs in the system. Such a system can also work with conventional solid fuel boilers if an external microcontroller is used to control it.

Considering its functions, this type of pipe fittings usually has a common ball design, activated by an electric drive when the valve operating mode changes. A three-way valve can be connected to a temperature sensor directly through a servo drive. In this case, a ball valve or one with a secretory distribution element is used.

Materials of manufacture

The three-way valve can be made of bronze, cast iron or stainless steel. It is suggested to select a material that can withstand high thermal loads.

Application

Valves for regulating the mixing of water into heating systems are used in recirculation systems with adjustable coolant temperature. They are supplied with hydraulic piping pellet boilers. In solid fuel boilers, it is possible to install an external microcontroller that controls the air supply, as well as a three-way valve that stabilizes the temperature indicators of the coolant supply to the system without a hydraulic arrow and expensive pumping groups. Such solutions are applicable for heating solid fuel boiler heating circuits designed for lower coolant temperatures.