Balancing valves control and balance the fluid flow between various system sections in fluid systems, including HVAC systems. It helps keep the flow rates and pressures regular across the system. The balancing valve ensures that every branch and circuit gets what it needs. Correct selection and installation are vital for proper functioning. They balance the pressure in the system to provide the inside of the structure with the required temperature. It minimizes energy use and maintenance costs.

The function of a balancing valve is to fix any fluid flow problems caused by changes in line lengths or pressures within the system. Changes in elevations, mechanical losses, or different demands from different parts or zones of the system can all cause these changes.

The following article gives the basics of balance valves. It covers how it works, different types of balancing valves, and how they are usually used. In the end, we will explain the balancing valve’s advantages, applications, and size. 

How Does a Balancing Valve Work?

• Hydronic Circuits

The flow of liquids in an HVAC system is constantly changing. It changed with changes in the building’s conditions. If you build and establish your HVAC systems correctly, they should be able to give you the correct energy when and where you need it.

• Unbalanced System 

Water will flow where it gives it the least amount of trouble. If a system isn’t adjusted, it could underflow or overflow. This could cause too little or too much heating or cooling. The “resistances” by lines of different lengths ensure that rooms from the pump get less water. Head loss goes up as the pipe gets longer, turns, gets more narrow, and gravity.

• Balanced System 

Adding the right degree of “resistance” to all lines is done by balancing valves. This ensures the system distributes the correct flow and temperature to all ends. It is always taking into consideration the facility’s current conditions.

What Are the Main Types of Balancing Valve?

Static Balancing Valves

                                                        Figure 1 Static balancing valve

Static balancing valves are also called digital locking balancing valves and manual balancing valves. Static balancing valves are not susceptible to changes in system pressure. Instead, static balancing valves are modulating valves that require manual adjustment. This determines the pressure decrease across the valve. An assist in attaining flow values that align with the design. It is provided by a test and balance evaluator, who measures pressure loss and calculates flow. It helps to adjust valve holes. After determining the settings for these valves before installation, those settings are modified during field installation. Internal valve components remain static while the system is in operation.

This manual operation maintains a balanced system under full-load conditions (design load). However, it operates only 2% to 3% of the time under such conditions. However, the system becomes unbalanced when the dynamics deviate even slightly. This state persists until the system is reevaluated and modified.

Operation and Installation of Static Balancing Valve

A static digital lock balance valve comprises a locking mechanism, an opening degree indicator, and a pressure measuring valve of a small design to facilitate flow measurement. Once the appropriate standard balance valve is installed for each branch and user inlet, only one use of a specialized smart device is required to correct the issue. After locking, the system’s overall water volume can be maintained within an acceptable range. Thus, the “large flow, small temperature difference” is overcome.

Main Advantage of Static Balancing Valves

Environmentally Friendly: 

Static balancing valves use less energy and less non-renewable resources than automated valves.

Sensitive: 

Static balancing valves precisely measure low flow rates.

Intuitive: 

Maintaining a static balancing valve is simpler when an issue arises than an automatic valve.

Cost-effective: 

By consuming less energy than automatic valves, static balancing valves help reduce energy costs.

Technical Specifications of Static Balancing Valve

• Normal prussure：PN≤1.6Mpa
• Working medium: Water, Ethylene glycol mixture
• Working temperature：-20℃≤T≤120℃
• Connection end：3/4″~2″ female thread
• Testing port connection end:1/4″ female thread

Size of Static Balancing Valve

Fixed-Orifice Balancing Valves 

                                       Figure 2 Fixed orifice balancing valve

It has a set orifice, like a Venturi insert, and pressure/temperature ports. These ports allow you to measure the difference in pressure across this orifice. Since the opening stays fixed while the valves are being adjusted, it is easy to determine the system’s flow rate by measuring the pressure drop across the ports. When launching, this kind of hand balance valve works better.

Advantages:

Fixed orifice designs are more accurate than variable orifice designs. They are also easier to set up and require fewer connections, which lowers the installation cost.

Automatic Balancing Valves

Dynamic and pressure-independent balancing valves are alternative names for automatic balancing valves. These valves aim to optimize system operation by sustaining a constant flow rate. However, variations in differential pressure. These valves function more under variable load conditions than static balancing valves. Their internal components are mobile to compensate for changes in differential pressure.

By regulating variations in system pressure within the valve, automatic balancing valves function as pressure differential regulators under most load conditions. This makes them more user-friendly.

Advantages of Automatic Balancing Valves

• User-friendly:

Automatic balancing valves self-adjust, eliminating the need for balancing capability or costs. 

• Efficient:      

By preventing overpumping at part load, automatic balancing valves decrease pumping costs. It ensures uninterrupted water flow, which improves boiler efficiency. 

• Long-lasting and quiet: 

Minimizing water noise and erosion contributes to the system’s longevity. 

• Time-efficient:      

Since the valves balance automatically, there is no need for manual help. System rebalance is required when terminal units are reconfigured within the system.

Pressure-Independent Flow Control Valves 

                                    Figure 4 Pressure-independent flow control valves

All-in-one devices with pressure-independent flow control valves perform the work of balance valves, control valves, and differential pressure regulators. They have differential pressure regulators that adapt to changes in system pressure. This keeps the flow steady in the heating or cooling parts to meet different temperature needs. Pressure-independent control valves can be paired with motors that allow you to control the flow from a distance.

Applications of Static Balancing Valves vs. Automatic Balancing Valves

Automatic and static balancing valves are advantages in many uses. Contingent upon the specific demands of the given system.

• Applications for Static Balancing Valves 

For Domestic Hot Water Recirculation Lines: 

Static balancing valves can effectively regulate water flow through a plumbing system.

Power Generation Systems:

Static balancing valves are compatible with variable speed flow. It controls systems in power generation systems.

HVAC Systems:

Static valves perform well in facilities with frequent low flow rates.

• Applications for Automatic Balancing Valves

Fan Coil Units: 

Automatic balancing valves are more effective regulated fan coil units.

HVAC System:

Automatic balancing valves are particularly effective in HVAC systems. It requires a uniform air passage throughout the facility.

Applications of Balancing Valves

Balancing valves are typically used for hydronic balancing. This process optimizes water distribution within a hydronic heating. It is a cooling system that balances fluid pressure. Ultimately, balancing valves assure the following by attaining equilibrium within these systems:

• Operating costs are lowered
• Correct temperature levels are reached and maintained
• Optimization of energy used  

Use of Balancing Valves in Hydronic Systems:

                                                              Figure 5 Applications

The installation and operation of balancing valves are fundamental to hydronic systems. Hydronic systems use water as the medium for both heating and chilling. Consider the application of compensating valves to hydronic systems.

• In-floor Heating:

In subfloor heating, balancing valves play a critical role. They regulate the passage of hot water through subfloor pipelines. Balancing valves help in the uniform distribution of heat throughout the floor. The entire chamber is heated.

• Radiators:

In hydronic systems, balancing valves are considered standard equipment. They regulate the discharge of hot water to radiators. They ensure the provision of adequate hot water to each radiator. It facilitates the system’s heating process. Balancing valves ensures that heat is distributed throughout the structure. It ensures certain areas maintain a cool temperature while others are prevented from overheating.

• Air Handling Units:

These units are required to convey conditioned air in larger structures. These units are equipped with balancing valves that maintain the flow of hot or cold water. They have an impact on the temperature and vapor. Balancing valves contribute to the preservation of a balanced environment.

• Fan Coil Units:

Fan coil units are cooling & heating devices for hydronic systems. Balanced water supply is regulated by balancing valves to these units. Balancing valves function to ensure that each unit has the ideal temperature. It optimizes various zones or spaces within a design.

• Heat Exchangers:

Through the use of heat exchangers, one liquid is converted to another. Balancing valves function by regulating the flow of fluids to the heat exchangers. It facilitates effective thermal transfer. Balancing valves ensures the proper circulation of thermal energy. It optimizes the performance of the system.

• Chilled Beams 

Walls or ceilings are outfitted with chilled beams used to cool hydronic systems. Balance valves control the passage of chilled water to these beams. It provides precise cooling that is effective. The use of balancing valves prevents inadequate or excessive cooling. It ensures that the temperature remains optimal for the entire area.

• Sizes of Balancing Valves

There are many dimensions of balancing valves on the market. It ranges from those designed for domestic use to those intended for industrial applications. At the same time, 1/2-inch to 12-inch is the typical range. Larger dimensions are available for particular industrial applications. Typically, the pipe diameter dictates the valve size within the system.

When determining the suit balancing valve size, it is vital to consider the system’s pipe configuration and the required flow rate. Choosing a valve that is large or small can have an impact on the system’s balance and efficacy.

It is suggested to find guidance from a technical specialist. You can use a sizing chart supplied by the manufacturer. It helps you determine the appropriate balancing valve size for a given application.

Conclusion 

For commercial buildings or industrial companies, use an effective HVAC system. They must have balancing valves. Some costs and issues come with balance valves, but their pros are more than cons. Installing them reduces energy use. Moreover, it makes HVAC parts last longer. It allows people to control their temperatures and lower system noise. But remember that balance valves need to be maintained regularly. It is limited to complete under your control. When this valve is checked and kept, balancing valves keep any HVAC system reliable.