Shut-off valves Manufacturers online

Shut-off valves are mechanical components used in piping systems to control, regulate or completely shut off the flow of liquids or gases.

They are often used in heating, sanitary, industrial and gas systems and offer the possibility of either completely opening or closing the flow. It is also possible to close the valves only partially to throttle the flow.

Below is an overview of the function, types and use of shut-off valves, their advantages and disadvantages as well as existing restrictions:

How shut-off valves work:

The way a shut-off valve works depends on its design. In general, the flow is shut off or released by the movement of a closing element located in a valve seat.

To close the valve, a closing element, such as a wedge, ball or disk, is moved into the flow path of the pipeline by a rotary movement of a handwheel or another, also electrically operated, actuating device, thus blocking the flow. To open the valve, the closing element is pulled back out of the flow path by the actuating device, allowing the medium to flow freely through the pipeline again. In some types of shut-off valves, the flow can also remain partially open in order to regulate or throttle the flow. However, not all shut-off valves are suitable for precise flow control.

Types of shut-off valves:

There are different types of shut-off valves, each suitable for specific applications. The most important types are:

• Ball valve (ball gate valve): Here, a spherical disk with a through hole is actuated by a 90-degree turn. If the hole in the ball is aligned with the pipe, the medium can flow through. With a 90-degree turn, the ball closes the passage completely. Application: Ideal for quick opening and closing operations and is commonly used in gas, water and oil pipelines.
• Gate valve: A vertically moving gate valve (often referred to as a "wedge") is lowered or raised into the flow path to block or release flow. It is a linear valve that is mainly used to fully open or close the flow. Application: In pipelines with high flow velocity or high pressure, especially in water or sewage systems.
• Butterfly valve (flap valve): A round or oval disk that rotates around a central axis. Turning the disk 90 degrees opens or closes the flow. These valves are space-saving and offer good control for large flow rates. Use: In ventilation systems, large water lines or in applications where fast switching operation is required.
• Needle valve: A fine control valve that provides very precise flow. A small, tapered pin (needle) moves into a small seat to throttle or close the flow. Use: In applications requiring fine control of flow, such as pneumatics or precision controls.

Use of shut-off valves:

Shut-off valves have specific uses in various fields:

1. Plumbing:
Shut-off valves are often used in homes and commercial buildings to control the flow of water or to isolate individual areas of the system during maintenance work.

2. Heating systems:
Shut-off valves are used in heating systems to isolate specific parts of the system, for example when servicing radiators or boiler systems.

3. Industrial applications:
In industrial systems where liquids, gases, steam or chemicals are transported, shut-off valves are important to control the system and keep operations safe and reliable.

4. Gas systems:
Shut-off valves play a crucial role in gas supply systems to control the flow of gas and shut it off in an emergency. Ball valves are particularly popular here.

5. Ventilation and air conditioning systems:
Shut-off valves are used in ventilation systems to control or shut off the air flow, e.g. in air conditioning or exhaust air systems.

Advantages of using shut-off valves:

• Shut-off valves allow quick and easy control of the flow. Ball valves and butterfly valves, for example, can open or close the flow completely with a 90-degree turn.
• Many shut-off valves, especially those made from high-quality materials such as stainless steel, are highly resistant to corrosion and pressure, making them ideal for industrial applications.
• Shut-off valves generally offer a high level of tightness, which is particularly beneficial in gas or water applications to prevent leaks.
• Available in various designs, shut-off valves offer a high degree of flexibility in terms of installation and application. They can be configured in different sizes and pressure classes.

Disadvantages and limitations:

• Some shut-off valves, such as the ball valve or the gate valve, are not ideal for precise flow control. A needle valve is more suitable here.
• Some valve types, such as gate valves, require more space as they have a large stroke range. This can be problematic in tight installations.
• Some valve types, such as shut-off valves with discs, can suffer mechanical wear due to frequent opening and closing.

Shut-off valves are critical components in piping systems that are used to control or block the flow of liquids and gases. They are available in various types and designs, such as ball valves, gate valves, flap valves, needle valves and classic shut-off valves. Each type offers special advantages, depending on the requirements and area of application. Shut-off valves are characterized by easy handling, high tightness and robustness, but have limitations when it comes to precise control or space conditions.

Here is an overview of the most important criteria to look out for when buying shut-off valves:

When purchasing shut-off valves, there are several important factors that need to be considered to ensure that the valve is suitable for the specific application and will work reliably.

• The design should be matched to the control and flow requirements in the system:
• Ball valve: quick and easy to operate, ideal for applications where the valve needs to be opened and closed frequently.
• Gate valve: Well suited for larger pipe diameters and high volume, provides full flow.
• Butterfly valve: Space-saving and efficient, especially for large pipelines and lower pressure applications.
• Shut-off valve (screw valve): Ideal for more precise flow control and throttling of flow.
• There are manual and automated shut-off valves. The choice depends on the complexity of the system and the desired automation:
• Manual shut-off valves: Inexpensive, but require regular monitoring and manual operation.
• Automated valves: Are controlled by electric, pneumatic or hydraulic actuators. Ideal for systems that are difficult to access or automated, but more expensive to purchase and maintain.
• The valve must be matched to the medium (water, gas, oil, steam, chemicals) and the specific requirements of the application.
• Water: Standard materials such as brass or stainless steel are sufficient.
• Gas: Special gas safety valves are required here, usually in combination with certified sealing materials.
• Chemicals: Corrosion-resistant materials such as stainless steel or special plastics are required.
• Steam: High-pressure and high-temperature valves are required, often made of robust materials such as stainless steel or cast iron.
• The material of the shut-off valve plays a decisive role in its service life and suitability in different environments:
• Brass: Suitable for water, gas and general heating applications.
• Stainless steel: Excellent for corrosive media, high temperatures and aggressive environments.
• Cast iron: Robust choice for large industrial applications, especially high pressure and volume.
• Plastic: Used in chemical applications or low pressure requirements where corrosion resistance is required.
• The nominal pressure of the valve must be at least as high as the maximum operating pressure of the system.
• PN 16, PN 25, PN 40: These classifications indicate how much pressure the valve can withstand at a certain temperature.
• If the nominal pressure is too low, this can lead to safety risks and valve damage.
• The valve must be able to withstand the temperature requirements of the application to avoid deformation or material fatigue:
• Low temperature applications: Plastic valves or brass valves are usually sufficient.
• High-temperature applications (steam, hot water, thermal oils): Heat-resistant materials such as stainless steel or special high-temperature seals are required here.
• The seals of the shut-off valve must be chemically and thermally resistant:
• NBR (nitrile rubber): Well suited for water, oils and general applications at lower temperatures.
• EPDM (ethylene propylene diene rubber): Resistant to hot water and steam, ideal for heating and plumbing applications.
• PTFE (Teflon): Excellent for chemically aggressive media and high temperatures.
• Viton: Resistant to high temperatures and chemicals.
• The correct size ensures that the flow is regulated efficiently and that the valve does not represent a bottleneck in the system.
• The nominal size (DN) of the shut-off valve must match the pipe system. Standard sizes range from DN 15 (1/2 inch) to DN 200 and beyond.
• A valve that is too small can restrict the flow, while a valve that is too large can cause imprecise control and higher costs.
• Shut-off valves are available with different connection types, which must match the piping installation:
• Threaded connections: For smaller installations, easy to fit.
• Flanged connections: For larger systems and higher pressures, well suited for industrial applications.
• Welded connections: Durable and safe, especially in high pressure or high temperature systems.
• The maintenance requirements of the shut-off valve should be considered when selecting:
• Manual valves: Easy to maintain, but usually require the system to be shut down.
• Automated valves: Electric motorized or pneumatic actuators can facilitate operation, but require additional maintenance infrastructure.
• The shut-off valve should meet all necessary standards and certifications to comply with safety and quality standards:
• DIN standards or ISO certifications guarantee that the valve complies with international standards.
• Special gas safety certificates or drinking water approvals (DVGW) are necessary for applications in these areas.
• The price of a shut-off valve depends on the material, design and size. It is important to consider not only the purchase costs, but also the long-term maintenance costs.
• High-quality valves are often more expensive, but offer a longer service life and reduce the need for replacements and repairs.
• An investment in high quality valves often pays off in the long term through fewer breakdowns and lower maintenance costs.

By carefully considering these aspects, you can ensure that the shut-off valve meets the requirements of your application and ensures high efficiency and longevity.

Shut-off valves can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Stop valves from all over the world can be found on Exportpages.