Q: What is the application of a zone valve?

A: Zone valves are typically used in closed-loop hydronic heating/cooling systems in residential or commercial buildings that use fan coils, baseboards, or radiators. These valves control the liquid flow within the system, regulating temperature in different areas. The system is often filled with water mixed with up to 50% glycol solution to prevent freezing during winter months. The building is divided into separate zones, each controlled by a zone valve, enhancing energy efficiency and comfort by only heating or cooling necessary areas.

Q: Besides temperature control, can a zone valve be used elsewhere?

A: No. Zone valves are designed specifically for closed-loop hydronic systems, which are separate from domestic water supply systems and use water and glycol as media. Using them in an open-loop system, such as city water, will cause internal damage. Dissolved oxygen in city water can corrode the valve’s components, shortening its service life, and high water pressure may prevent the valve from closing completely, leading to leaks.

Q: How does a zone valve work?

A: A zone valve consists of two main parts: an actuator and a valve body. The actuator contains a motor, a spring, and other mechanical components. When power is supplied, the motor winds up the spring, moving the valve’s internal paddle to the open position. When power is turned off, the spring automatically returns the paddle to its original position, closing the valve.

Q: There are two types of your zone valves, with end switch and without end switch. What is the difference?

A: Valves with an end switch have two additional wires (usually blue and red) that indicate the position of the valve paddle. Normally, these wires are open-circuit. When the valve is fully open, the end switch closes the circuit, sending a signal to the boiler or pump to start circulating water throughout the system. This function allows the pump to run only when needed, improving system efficiency.

Q: What do “N.C.” and “N.O.” mean?

A:

• N.C. (Normally Closed): Valve remains closed when no power is supplied.
• N.O. (Normally Open): Valve remains open when no power is supplied.

All our zone valves are N.C. type, meaning they remain closed in the absence of power.

Q: What is the difference between “static pressure” and “close-off pressure” in your user manual?

A:

• Static Pressure: The maximum pressure the valve body can withstand during testing without leakage, indicating the valve’s structural strength.
• Close-Off Pressure: The maximum pressure under which the valve’s internal components can fully open or close the valve without malfunctioning. This value is essential for determining the valve’s operational limits in the system.

Our valves have a static pressure rating of 290 PSI and a close-off pressure ranging from 20 to 50 PSI, depending on valve size. Larger valves generally have lower close-off pressure due to the increased force needed to move a larger internal paddle.