Heating ventilation air conditioning valves (also known as HVAC valves ) are devices used to control the flow of fluids (e.g., water, steam, refrigerant, etc.) in an HVAC system. The HVAC field encompasses a wide variety of equipment, including central air conditioners, boilers, heat pumps, rooftop units, furnaces, packaged units, and chillers, all of which rely on the controlled movement of water, steam, and coolant gases. This control is achieved through the strategic use of various valves. By adjusting valves, parameters such as temperature, pressure, and flow rate of the system can be precisely controlled to ensure efficient, safe, and reliable operation.
This article will provide a detailed classification of HVAC valves to assist users in solving fluid-related problems.
Types of HVAC valves
There are numerous varieties of HVAC valves, and this article will focus on nine of the most prevalent ones.
1. Gate Valves
Structural features: The valve body is equipped with the plane gate which is perpendicular to the media flow direction and relies on the lift of the plate to open or close the media path. Because of this, the gate valve can only be fully open and fully closed. It can not be adjusted but can withstand the pressure of the medium from both directions.
Function: Gate valves can effectively cut off the medium in the pipeline. By opening and closing the pipeline, they can control the flow direction, adjustment, control of the transport medium. Gate valves feature small flow resistance, strong sealing, high pressure and high temperature resistance, but relatively slow opening and closing speed, more suitable for less frequent operation occasions.
Taloar gate valves can be divided into rising and non-rising steam gate valves, metal and resilient seated gate valves. Metal seated gate valves have solid wedge plate, bolted bonnet and cast bronze seat, which feature good tightness and long service life. Resilient seated gate valves use EPDM fully wrapped plate, to ensure zero leakage. The shell inside and outside is sprayed with epoxy resin. Body materials include cast iron, ductile iron, cast steel and stainless steel. The medium is suitable for water, oil, gas (WOG), commonly used in water, sewage treatment, petrochemical, chemical industry, power generation and other industries.
2. Ball valves
Structural features: The headstock piece ball is a spherical hole. The opening and closing parts for the ball are driven by external force on the upper end of the valve stem, enabling the closing parts (ball) to rotate 90°around the center line of the valve body. This allows the valve to perform a variety of functions, including cutting off, connecting, distributing, or changing the direction of flow.
Function: The ball valve is designed for rapid closure and opening of fluid pathways. It is a high-performance, quick-acting valve.
The material of Taloar’s ball valve shell is alloy, available in bronze or brass. The bronze variant contains metal tin, offering high tensile strength and elongation, as well as excellent corrosion resistance, longevity, and performance. These attributes make it a superior choice compared to brass material valves.
Structural features: The butterfly valve features a disc-shaped butterfly plate within the valve body that is capable of rotating around its own axis, enabling the valve to open, close, or regulate.
Function: The butterfly valve is designed to regulate and control the flow of fluids. When the plate is rotated to the closed position, it completely covers the valve seat, thereby ensuring a complete blockage of the fluid. The valve plate can be adjusted to control the flow rate of the fluid, making it ideal for pipeline systems that require large-diameter flow regulation.
Taloar concentric butterfly valve features a high-precision valve plate with low wear between the valve and seat, ensuring zero leakage. The valve seat features an EPDM and NBR groove plunging design, which provides a completely sealed connection to the valve body and reduces the gap. The mechanical assembly is designed for smooth operation with low friction and light torque. The seat features a sealing waterline on both sides, enhancing the sealing performance and eliminating the need for a flange gasket. A three-stage O-ring seal is employed between the valve stem and the sleeve to guarantee leakage-free performance. The valve body is designed with lugs for convenient positioning and installation, and the connecting flanges are compatible with BS EN/ANSI/GB standards.
4. Globe valves
Structural features: The globe valve is designed to control the flow of fluid by regulating the valve plate rise and fall. This enables the valve to be used for cutting off or regulating fluid. As the valve stem is rotated, the threads convert the rotary motion into linear motion, pushing the valve plate up. Once the valve plate has been dislodged from the valve seat, the fluid will begin to pass through the valve. As the valve plate rises, the cross-sectional area of the fluid passing through increases, resulting in a higher flow rate.
Function: The primary function of the globe valve is to cut off the fluid. Globe valves can be adjusted to alter the valve plate opening, allowing for the regulation of fluid flow and pressure within pipelines. They are well-suited for situations where precise control over fluid movement is required. Globe valves are typically designed for unidirectional flow, preventing the medium from flowing in reverse. This one-way sealing effect is a key feature of globe valves.
5. Check valves
Structural features: It is important to note that the check valve is a crucial component of the HVAC system. The main function of a check valve is to automatically open and close in response to the flow of media and pressure, preventing backflow. Check valves can be classified according to their structural characteristics, including horizontal swing check valves, silent check valves, dual plate check valves, and ball non-return check valves.
The function of the check valve is to prevent the backflow of the medium, which can damage the pump equipment located behind the valve. Additionally, it reduces the occurrence of water hammer and pipeline vibration, as well as noise.
Taloar silent check valve is driven by a spring valve plate in the center of the valve shaft and is designed to automatically reset. The opening pressure is minimal. The top of the center guiding shaft and the fixing groove are hexagonal in design and closely fitting, ensuring that the valve plate remains stationary during operation. This prevents the medium from experiencing a rapid backflow, which could otherwise cause turbulence and result in increased pipeline vibration and noise.
6. Balance valves
Structural Features: By modifying the clearance between the spool and the valve seat, the opening height can be adjusted to alter the resistance of the fluid through the valve, thereby regulating the flow. This article focuses on two types of flow balance adjustment valves: balance regulating valves and auto-flow balance valves.
Balance regulating valves are an effective solution for addressing hydraulic imbalances in air conditioning and heating systems, particularly at the end of the system and in the loop. Taloar’s balance regulating valves are designed with a Y-shaped structure, offering full flow, low resistance, stable flow, and easy adjustment. The high-precision cone-shaped throttle plug ensures precise measurement, shut-off, and flow regulation. The digital display is highly accurate and the window is equipped with a patented dust cover to avoid scale contamination. The locking memory function prevents water impact and human error operations from affecting the original adjusted flow value. A zigzag ball valve is installed at the front of the measuring point for shut-off and servicing purposes. For convenient measurement, stainless steel fittings are extended on the outside of the insulation
Auto-flow balance valves guarantee a constant flow rate by automatically adjusting the position of the spool
during pressure fluctuations through a specially designed flow regulating mechanism, thereby limiting the
amount of flow passing through. The valve typically sets a flow limit that prevents excessive flow even when
system pressure increases. It has the capability to:
Maintain a constant flow rate: The flow rate
remains stable regardless of pressure fluctuations.
Automatically adjust the flow: It is designed to
automatically adjust the flow in response to changes in pressure.
7. Differential pressure control valves
Structural Features: The objective of differential pressure control valves is to automatically adjust the valve opening in response to pressure differences within the piping or equipment system. This is achieved by adjusting the valve opening according to the set value of the pressure difference, thereby ensuring that the pressure difference remains stable during system operation.
Function: The product offers automatic constant differential pressure without the need for an external power source. The long-stroke adjustment spring allows for a wide differential pressure adjustment range, excellent performance, and on-site setting of the differential pressure value.
Taloar’s differential pressure control valves are constructed with high-strength stainless steel spools and diaphragms, a Y-type design, and are capable of full flow with low resistance and stable operation, offering users easy adjustment capabilities. The valve is equipped with a high-pressure chamber vent and pressure measurement connections on both sides, allowing for comprehensive monitoring and control. A ball valve is installed in front of the measuring point for shut-off and maintenance purposes. The stainless steel fittings are positioned outside the insulation, allowing for straightforward measurement.
Structural features: The motorized control valve receives signals from the control system and, in response, the electric actuator produces the corresponding rotation or linear motion, which is transmitted to the valve stem. This enables the spool to change the opening in the valve body, thereby regulating the flow of fluids, pressure, and other process parameters. The control system is designed to continuously adjust the signal in accordance with the data fed back from the sensor, thereby enabling closed-loop control.
Function: Motorized control valves are designed to precisely regulate the opening of the valve in response to an electrical signal, offering high-precision control over flow, pressure, and temperature.
Take Taloar ES/BL series of motorized control valves as an example. Brass threaded motorized control valves are suitable for use in HVAC systems, refrigeration, and building automatic control systems. When all kinds of control signals are received from instruments and computers, it can adjust temperatures and pressures, control flows and liquid levels, and regulate other system parameters. It is primarily used for conveying cold and hot water, glycol solutions, and other media.
9. Pressure independent control valves
Structural features: The valve’s structural features enable it to adapt to system changes in real time, ensuring the stability of flow and pressure. This is achieved through the electric drive and feedback adjustment mechanism.
Function: It is a combination of a preset flow rate, dynamic balance, and electric control function. This integrated solution offers end-balance control.
Taloar pressure independent control valves have pressure independent valve characteristics, almost 100% valve performance to minimize energy consumption and arbitrary maximum flow setting for more precise control. Lockable flow set point. Flow control is related to actuator opening and is not affected by differential pressure fluctuations. It features multiple power input signal options, plug-in flow measurement point for quick connection and space saving installation.
Application of HVAC valves
HVAC valves are widely used in various areas of HVAC systems such as heating, ventilation, air conditioning, refrigeration and so on. They play an important role in shutting off, regulating, distributing and changing the direction of media flow under different operating conditions and media characteristics.
Selection and Maintenance
When selecting HVAC valves, factors such as the nature of the medium, the working pressure and temperature, the size of the pipework and the method of connection should be considered. At the same time, attention should be paid to the valve material, sealing performance, corrosion resistance, service life and other key indicators. In the process of use, the valve should be regularly inspected and maintained to ensure its normal operation and extend its service life.
As a professional valve manufacturer, Taloar is committed to providing each customer with the highest quality HVAC valves. If you need special customized products, please contact us.
If you need to keep up with innovations and technological advancements in HVAC valves, Taloar will support you! For more details, please contact sales@taloar.com or WhatsApp 008618112507128.
Copyright © TALOAR All Rights Reserved
