Double regulating valves are an important component in many heating, cooling and HVAC pipework systems. They are designed to provide both flow regulation and isolation, making them particularly useful when a system needs to be accurately balanced and controlled.
But what exactly is a double regulating valve, how does it work and where can it be used?
At Industrial Valve Outlet, we supply industrial valves to a wide range of industries and applications. In this guide, we'll explain what double regulating valves are, how they work and some of the most common applications where they can be used.
What Is a Double Regulating Valve?
A double regulating valve, often abbreviated to DRV, is a valve designed to regulate the flow of fluid through a pipework system while also providing a means of isolation.
They are particularly common in closed-loop heating and chilled-water systems, where it is important to balance the flow between different branches or circuits.
The regulating function allows the valve to be adjusted to achieve the required flow rate, while the isolation function allows the circuit to be shut off when maintenance or servicing is required.
Double regulating valves are therefore particularly useful in systems where both hydraulic balancing and isolation are required.
How Does a Double Regulating Valve Work?
A double regulating valve controls flow by adjusting the position of an internal component within the valve.
The valve can be set to a particular position to restrict the amount of water passing through a circuit. Once the system has been balanced, the valve's setting can generally be recorded so that it can be returned to the same position if it needs to be closed and subsequently reopened.
Many double regulating valves also incorporate pressure measurement points. These allow differential pressure to be measured across the valve, which can help commissioning engineers determine the flow rate and balance the system correctly.
The exact design, adjustment mechanism and available measurement features will depend on the particular valve.
What Is Hydraulic Balancing?
To understand why double regulating valves are used, it helps to understand the concept of hydraulic balancing.
In a heating or chilled-water system, water needs to be distributed correctly around the various circuits.
Without appropriate balancing, some circuits may receive too much flow while others receive too little. This can result in uneven heating or cooling and can affect the performance of the overall system.
Double regulating valves can be adjusted to control the flow through individual branches, helping to achieve the required distribution throughout the system.
For example, a large commercial building may have numerous heating or cooling circuits. Each circuit can have different resistance within the pipework, meaning water will not necessarily distribute evenly without some form of balancing.
By adjusting the double regulating valves, the flow through each circuit can be set to the required level.
What Are Double Regulating Valves Used For?
Double regulating valves are most commonly associated with HVAC and hydronic systems, although they can be used in other applications where accurate flow regulation and isolation are required.
Common applications include:
Heating Systems
Double regulating valves are widely used in commercial and industrial heating systems.
They can be installed on individual heating circuits to regulate water flow and help balance the system.
Applications can include:
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Commercial heating systems
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Industrial heating systems
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Central heating installations
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Radiator circuits
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Underfloor heating systems
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Heating distribution networks
Chilled-Water Systems
Double regulating valves are also commonly used in chilled-water systems serving commercial buildings, industrial facilities and other installations.
They can help balance the flow of chilled water to different branches, coils and other equipment.
Applications include:
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Chilled-water circuits
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Air conditioning systems
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Cooling coils
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Fan coil units
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Air handling units
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Commercial cooling systems
HVAC Systems
HVAC installations often contain multiple branches that need to receive the correct amount of heating or cooling water.
Double regulating valves can be installed on these branches to assist with balancing and flow control.
They are commonly found in:
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Offices
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Schools
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Hospitals
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Hotels
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Retail buildings
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Industrial premises
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Commercial developments
District Heating and Cooling
Double regulating valves can also be used in district heating and cooling systems where water needs to be distributed across multiple circuits and buildings.
The ability to regulate and isolate individual sections of the system can be useful for both commissioning and ongoing maintenance.
Industrial Process Systems
Depending on the valve specification and the medium being handled, double regulating valves may also be suitable for certain industrial process applications where flow regulation and isolation are required.
The valve's materials, pressure rating, temperature rating and compatibility with the process medium should always be considered before selection.
What Are the Benefits of Double Regulating Valves?
Double regulating valves offer several useful features for heating and cooling systems.
Flow Regulation
The valve allows the flow through a circuit to be adjusted to the required level.
This can be particularly important when balancing systems containing multiple branches.
System Balancing
Correctly adjusted double regulating valves can help distribute water more evenly throughout a heating or chilled-water system.
This can help ensure individual circuits receive the flow required by the system design.
Isolation
In addition to regulation, the valve can provide isolation when a circuit needs to be shut off for maintenance or servicing.
This means a separate isolation valve may not always be required at the same location, depending on the system design and valve specification.
Commissioning
Many double regulating valves can be used as part of the commissioning and balancing process.
Differential pressure measurements taken across the valve can help engineers determine the flow passing through the circuit and make adjustments where necessary.
Repeatable Settings
Many designs allow the valve setting to be recorded.
This can make it easier to return the valve to its previous regulating position after maintenance or servicing.
Double Regulating Valves vs Standard Isolation Valves
A standard isolation valve is primarily designed to turn flow on or off.
A double regulating valve provides additional functionality by allowing the flow through a circuit to be adjusted and balanced while also providing isolation.
For example, a ball valve may be suitable when a pipe simply needs to be opened or closed. However, if a heating or chilled-water system needs to have its individual branches balanced to achieve specific flow rates, a double regulating valve may be more appropriate.
The correct choice depends on the requirements of the system and the intended function of the valve.
Double Regulating Valves vs Balancing Valves
The terms double regulating valve and balancing valve are sometimes used interchangeably, but valve designs and features can vary between manufacturers.
A double regulating valve is generally intended to provide both regulation and isolation, whereas different types of balancing valves may offer different measurement, adjustment and control capabilities.
When selecting a valve, it's important to look beyond the name and check the manufacturer's specifications, particularly regarding flow measurement, pressure ratings, temperature ratings and the required application.
Where Are Double Regulating Valves Installed?
Double regulating valves are typically installed on individual branches or circuits within a larger pipework system.
For example, in a commercial building with several heating circuits, a double regulating valve may be installed on each branch. The valves can then be adjusted during commissioning to achieve the required flow through each circuit.
They may also be installed near items of equipment such as heating or cooling coils, depending on the design of the system.
The exact location should be determined by the system designer or commissioning engineer.
How Do You Choose the Right Double Regulating Valve?
Several factors should be considered when selecting a double regulating valve.
Pipe Size
The valve needs to be suitable for the size of the pipework and the required flow rate.
Medium
Double regulating valves are commonly used with water-based heating and cooling systems, but the valve must be compatible with the particular medium being handled.
Temperature
The operating temperature should be checked against the valve's specifications, particularly in heating and cooling applications.
Pressure
The valve must be suitable for the system's operating and maximum pressures.
Flow Rate
The required flow rate is an important consideration when selecting and setting a regulating valve.
Connection Type
Double regulating valves are available with different connection configurations, so the valve needs to be compatible with the existing pipework.
Measurement Requirements
If the valve is going to be used for system commissioning and balancing, consider whether differential pressure measurement points or other commissioning features are required.
Valve Material
The body and internal components need to be suitable for the medium and operating conditions.
For water-based systems, common materials may include brass, bronze, cast iron or ductile iron, depending on the valve design and application.
Double Regulating Valves in Commercial Buildings
Commercial buildings are one of the most common environments where double regulating valves can be found.
Large buildings often contain extensive heating and chilled-water systems with multiple branches serving different areas.
These can include:
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Office buildings
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Hotels
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Shopping centres
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Hospitals
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Schools and universities
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Leisure facilities
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Industrial buildings
Using regulating valves on individual circuits allows the system to be balanced during commissioning and adjusted when required.
A properly balanced system can help ensure that heating and cooling equipment receives the flow required by the system design.
Double Regulating Valves in Industrial Applications
Double regulating valves aren't limited to commercial HVAC systems.
They can also be used in industrial facilities where water or compatible fluids need to be distributed between multiple circuits.
Potential applications include:
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Industrial cooling systems
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Process water systems
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Manufacturing facilities
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Factory heating systems
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Cooling-water circuits
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Industrial HVAC installations
For industrial applications, it is particularly important to check the valve's pressure, temperature and material compatibility before installation.
Why Is Correct Valve Selection Important?
Choosing the correct double regulating valve is important for the performance and reliability of the system.
Selecting a valve based solely on pipe size may not be sufficient. The valve also needs to be suitable for the operating pressure, temperature, flow rate and medium.
The valve's connection type and available adjustment and measurement features should also be considered.
Where a valve is being used as part of a system balancing strategy, it should be selected and set in accordance with the requirements of the system design.
Industrial Valve Outlet: Double Regulating Valves
At Industrial Valve Outlet, we supply industrial valves for a wide range of industries and applications.
We understand that valve selection depends on much more than simply choosing the correct pipe size. Factors such as operating pressure, temperature, medium, flow requirements and connection type all need to be considered.
If you're looking for a double regulating valve for a heating, chilled-water, HVAC or industrial application, our team can help you identify a suitable valve for your requirements.
Find the Right Double Regulating Valve for Your Application
Double regulating valves provide an effective way to combine flow regulation, system balancing and isolation within a single valve.
They are particularly useful in heating, chilled-water and HVAC systems where achieving the correct flow through individual circuits is important for the performance of the overall installation.
From commercial buildings and industrial facilities to district heating and cooling systems, the correct double regulating valve can form an important part of a properly balanced pipework system.
Looking for a double regulating valve for your application?
Get in touch with Industrial Valve Outlet to discuss your requirements and find out more about our range of industrial valves. Email sales@industrialvalveoutlet.com or contact us on +44 (0)1482 697583.