What is the difference between EK 1/2 and VK 1/2 valves in practice

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In everyday practice, many customers and even some installers confuse the markings of EK and VK valves, although these are two distinct connection systems with different constructions. While the EK valve represents a standard straight or angled valve with an internal thread for a thermostatic head, the VK valve is specifically designed to connect to a radiator via reducing couplings without the need for its own threaded outlet.

Difference in construction and connection method

The key difference lies in how the valve connects to the radiator body. An EK-type valve (for example, Thermostatic radiator valve - straight, EK x 1/2") has an internal G 1/2" thread directly machined on the bottom, into which the thermostatic head is screwed and which is directly mounted from below onto the radiator's expansion coupling. In contrast, a VK valve (such as VK valve, angled EK x 1/2") functions as a separate valve that is mounted onto radiator couplings, and the valve is then mounted onto it; this system does not require the valve to have its own thread for a direct connection to the radiator.

When to use EK valves and when to use VK valves

Ek valves are an ideal choice for standard residential heating, where radiators are already equipped with the appropriate couplings or where compactness and quick installation of a single unit are important. However, if you are working on the renovation of older systems or need a more flexible solution for different types of radiators with varying pipe distances, we recommend using the combination SWING2 PN10 set, straight version, which often uses principles similar to the VK system to compensate for inconsistencies.

VK valves are suitable if you have radiators with external threads or specific outlets where direct installation of EK is not possible.
Ek valves are more cost-effective for new buildings with standardized radiators.
Practical example: When replacing old cast iron radiators, we often encounter damaged original outlets; in such cases, the VK valve proves to be a more universal replacement.

Impact on arm length and aesthetics

The choice between these two systems directly affects the visual result and the length of the arm visible under the radiator. The EK valve typically has a shorter overall profile, as it integrates the coupling and regulation functions into one body, which is suitable for narrow spaces. In contrast, the VK system, which includes a separate valve and valve, can be a few millimeters longer, but offers greater flexibility in setting the angle and position.

Therefore, it is necessary to accurately measure the distance from the wall to the center of the radiator outlet when choosing. If this dimension is critical, for example, with low window sills, the longer VK construction may interfere with the proper function of blinds or lighting, while the compact EK valve will not cause any problems. It is therefore always necessary to check the technical parameters of the specific model before purchasing.

Installation procedures and practical experience

From my long-term experience, I can say that the installation of an EK valve is often faster, as it is sufficient to mount the valve onto the coupling and tighten the nut, with the thermostatic head being added at the end. The procedure for a VK valve is a bit more complicated, as the valve itself must first be mounted onto the radiator, ensuring a seal, and only then can the valve be mounted, which requires more time and precision. For those who prefer comprehensive solutions, there are also sets such as SWING2 PN10 set, angled version, which simplify the installation process.

One of the common mistakes during the installation of VK valves is insufficient tightening of the connecting parts, which can lead to water leakage. I therefore recommend using high-quality seals and following the tightening torque according to the manufacturer. For EK valves, it is also important to correctly set the arm length to avoid pressure on the radiator body, which could cause deformation or leakage in the future.

Maintenance and replacement of the thermostatic head

Both systems allow for the replacement of the thermostatic head, but with an EK valve it is often simpler, as the head can be replaced directly on site without the need to disassemble the entire valve from the radiator. With the VK system, replacing the head can be more difficult if the valve is firmly built-in and access is limited. In such cases, it is advisable to consider using valves that allow for replacement without draining the system, which is a topic we cover in our article on head replacement.

It is also important to know that, in long-term operation, problems with liquid jamming in the head can occur more frequently with VK valves if the temperature is not properly set or if the system is dirty. Therefore, regular inspection and system cleanliness are key to the long life of both types. If your valve gets stuck, we recommend reading our tips on solving stuck valves.

Technical Details: Types of Threads and Seals

A key technical difference is also the sealing method when connecting the thermostatic head. In EK valves, the sealing is located directly in the head and is usually a standard internal thread that ensures tightness when directly screwed into the valve body.

Practical Example: Replacement in Case of Damaged Outlets

In real practice, we most commonly encounter the problem of damaged outlets when replacing old radiators. If the original thread broke during disassembly or the radiator was deformed due to unprofessional intervention, using a standard EK valve is not possible, as there is nothing to screw into.

Frequently Asked Questions

Can I use an EK valve instead of a VK valve?

No, these systems are not interchangeable without modifications, as they have different connection methods to the radiator and different outlet constructions.

Is a VK valve more expensive than an EK valve?

They differ in price, but a VK valve can be more expensive due to a higher number of parts and a more complex installation, while EK is often a cheaper standard.

How can I determine which type I need for my radiator?

It is always best to check the technical specifications of your radiator or contact the manufacturer to determine the correct type of connection and arm spacing.

The correct choice between an EK valve and a VK valve depends on the specific situation on site, the type of radiator, and your installation requirements, so it is always a good idea to consult with a specialist before purchasing.

Do you have a question about this topic?

Are you unsure or dealing with a specific situation in your home? Write to us - we are happy to help.