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HVACR216 - HydronicsHVACR216 - Hydronics
Zone valvesZone valves
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2 way zone valve 2 way zone valve
• Hydronic heating systems often use two or more piping circuits to supply heat to different areas in a building.
• Such areas are called zones.
• One device often used to allow or prevent flow in a given zone circuit is called a 2 way zone valve.
• Hydronic heating systems often use two or more piping circuits to supply heat to different areas in a building.
• Such areas are called zones.
• One device often used to allow or prevent flow in a given zone circuit is called a 2 way zone valve.
32 way zone valve2 way zone valve
• Hydronic boiler with three zones• Hydronic boiler with three zones
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2 way zone valve2 way zone valve
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2 way zone valve2 way zone valve
• Several types of zone valves are available.
• They all consist of a valve body combined with an electrically powered actuator.
• Several types of zone valves are available.
• They all consist of a valve body combined with an electrically powered actuator.
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2 way zone valve2 way zone valve
Taco Honeywell B & G Taco Honeywell B & G
72 way zone valve2 way zone valve
• The actuator is the device which causes movement of the valve shaft when supplied with an electrical signal (voltage)
• The actuator is the device which causes movement of the valve shaft when supplied with an electrical signal (voltage)
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2 way zone valve2 way zone valve
• Some actuators use small electric motors and a gear train to produce a rotary motion of the valve shaft.
• These type of valves can move from fully closed to fully open in about 3 seconds
• Some actuators use small electric motors and a gear train to produce a rotary motion of the valve shaft.
• These type of valves can move from fully closed to fully open in about 3 seconds
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Electric motor with a gear trainElectric motor with a gear train
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2 way zone valve2 way zone valve
• Others use a heat motor that expands and contracts to produce a linear motion that moves the valves shaft up and down.
• Heat motor types require 2 – 3 minutes from when the electrical signal is turned on and the valve moves to the fully open position.
• Others use a heat motor that expands and contracts to produce a linear motion that moves the valves shaft up and down.
• Heat motor types require 2 – 3 minutes from when the electrical signal is turned on and the valve moves to the fully open position.
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Heat MotorHeat Motor
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Heat MotorHeat Motor
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2 way zone valve2 way zone valve
• On multiple zone systems, a separate zone valve is installed in the line going to or returning from each zone.
• Each zone valve is controlled by its own thermostat
• End switches in each zone valve control the Circulator and/or the burner/burner control
• On multiple zone systems, a separate zone valve is installed in the line going to or returning from each zone.
• Each zone valve is controlled by its own thermostat
• End switches in each zone valve control the Circulator and/or the burner/burner control
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2 way zone valve2 way zone valve
• Zone valves are available in two-wire, three wire, or four wire configurations.
• Two wires are always required to operate the valves actuator.
• The third, and in some cases the fourth wire is connected to an end switch.
• Zone valves are available in two-wire, three wire, or four wire configurations.
• Two wires are always required to operate the valves actuator.
• The third, and in some cases the fourth wire is connected to an end switch.
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2 way zone valve2 way zone valve
• All end switches are wired in parallel• All end switches are Normally Open
• The circulator and burner are also powered when any zone is calling for heat.
• A circulator pump is always required with zone valves.
• All end switches are wired in parallel• All end switches are Normally Open
• The circulator and burner are also powered when any zone is calling for heat.
• A circulator pump is always required with zone valves.
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2 way zone valve2 way zone valve
• End switches
– When the valve reaches the nearly open or fully open position, the end switch closes.
– The switch closure is used to signal other portions of the heating circuit that the zone is “calling” for heat.
• End switches
– When the valve reaches the nearly open or fully open position, the end switch closes.
– The switch closure is used to signal other portions of the heating circuit that the zone is “calling” for heat.
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2 way zone valve2 way zone valve
• When soldering a zone valve to copper tubing the actuator needs to be removed from the zone valve body.
• The disk or ball should be positioned away from the seat to prevent overheating
• When soldering a zone valve to copper tubing the actuator needs to be removed from the zone valve body.
• The disk or ball should be positioned away from the seat to prevent overheating
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2 way zone valve2 way zone valve
• All zone valves have a lever to manually override the motor and to open the valve in emergencies or for servicing.
• All zone valves have a lever to manually override the motor and to open the valve in emergencies or for servicing.
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4 zone hydronic system4 zone hydronic system
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Lever for manual valve operation
Zone valve motor
Valve cover
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Zone ValvesZone Valves
• Both two (2) way and three (3) way zones valves are available.
• The two way zone valve either allows full flow through the valve or totally stops the flow.
• This is the most commonly used zone valve in the residential application.
• Both two (2) way and three (3) way zones valves are available.
• The two way zone valve either allows full flow through the valve or totally stops the flow.
• This is the most commonly used zone valve in the residential application.
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Zone ValvesZone Valves
• Another type of zone valve is the Three way zone valve.
• A three way zone valve has an additional port called the bypass.
• When installed in certain piping arrangements, there is always flow through the valve.
• Another type of zone valve is the Three way zone valve.
• A three way zone valve has an additional port called the bypass.
• When installed in certain piping arrangements, there is always flow through the valve.
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Zone ValvesZone Valves
• Three way zone valve• Three way zone valve
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3 way zone valves3 way zone valves
• The three way zone valve is useful when flow must be maintained in a certain portion of the piping system.
• This is often necessary in modern low mass boilers with constant firing rates are used
• The three way zone valve is useful when flow must be maintained in a certain portion of the piping system.
• This is often necessary in modern low mass boilers with constant firing rates are used
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3 way zone valves3 way zone valves
• Three way zone valves can also be used as a diverter valve.
• When used in this application, the valve directs the incoming water flow into one of two possible outlets.
• Three way zone valves can also be used as a diverter valve.
• When used in this application, the valve directs the incoming water flow into one of two possible outlets.
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3 way zone valves3 way zone valves
• In some systems, three way zone valve functioning as a diverter valve, are used to direct hot water from the boiler either to the space heating distribution system, or an indirect water heater, but never both at the same time.
• In some systems, three way zone valve functioning as a diverter valve, are used to direct hot water from the boiler either to the space heating distribution system, or an indirect water heater, but never both at the same time.
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2 way and 3 way zone valves2 way and 3 way zone valves
• Most zone valves for residential and light commercial applications operate on a 24 VAC control voltage.
• Most zone valves for residential and light commercial applications operate on a 24 VAC control voltage.
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Taco zone valve wiringTaco zone valve wiring
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Honeywell zone valve wiringHoneywell zone valve wiring
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