Industrial ball valve with tightness class "A" is a critically important element of pipelines. Correct selection of shut-off valves minimizes the risks of cavitation, water hammer and system depressurization under operating load.
What is a ball valve and how does it work?
From a technical point of view, ball valve — is a type of shut-off valve, where the shut-off element is a sphere (ball) with a through hole.
- Working principle: Turning the ball 90° allows you to instantly open or close the flow.
- Importantly: The design is designed for only two positions. Using a tap to adjust the flow volume leads to rapid wear of the seals.
Main technical specifications
When designing highways, engineers rely on two key parameters: DN and PN.
1. Nominal diameter (DN)
DN (Nominal Diameter) is the nominal diameter of the internal cross-section of the pipe, expressed in millimeters.
- This indicator ensures the unification of parts from different manufacturers.
- For example, full-flow valve DN 25 mounted on a pipe with a suitable internal diameter of 25 mm, without creating additional flow resistance.
2. Nominal pressure (PN)
PN (Pressure Nominal) indicates the maximum permissible operating pressure in bar at an ambient temperature of +20°C.
- Cranes with markings PN 40 capable of withstanding pressures up to 40 bar.
- When choosing, it is important to consider the safety factor, since as the temperature increases, the working pressure usually decreases.
Housing materials and their purpose
Metal models dominate the industry due to their ability to withstand high pressure (up to 160+ bar) and extreme temperatures (over +200°C).
| Material | Application features | Advantages |
| Brass | Optimal for systems up to DN 50. | Corrosion resistance, reliability in household networks. |
| Carbon steel | High-pressure mains, petroleum products, steam. | High strength, resistance to deformation. |
| Stainless steel | Chemical and food industry. | Inertness to aggressive environments, no oxidation. |
Selecting a crane by type of environment
For water supply
The best choice is nickel-plated brass faucet with wear-resistant seat rings (PTFE). To minimize hydraulic losses, it is recommended to use only full-bore models.
For gas supply
Gas fittings undergo strict certification. Such valves have an elongated thread to increase the resistance of the connection to vibrations and are often marked with a yellow lever. On main gas pipelines they are used welded steel modifications.
For heating systems
Brass products with increased heat resistance are suitable for autonomous systems. In large centralized networks, they are used all-welded carbon steel cranes, capable of withstanding significant thermal expansion.
Connection types
The installation method is selected depending on the diameter and maintenance requirements:
- Coupling (threaded): For small diameters (up to DN 50).
- Flanged: For industrial systems where quick dismantling of the assembly is required.
- Welded: For the most critical areas where absolute tightness for decades is required.
Typical mistakes when choosing
- Flow adjustment: Attempting to use a ball valve as a throttle (half-open position) leads to cavitation wear of the ball and loss of tightness.
- Selection "by eye": Neglecting engineering calculations (pressure, temperature, chemical compatibility) creates a risk of accident.
Conclusion
A high-quality ball valve is a guarantee of the safety of the entire facility. In the assortment UKSPAR Certified fittings for any technical tasks are presented. Our specialists will help you make an accurate selection according to your project documentation and ensure shipment in the shortest possible time.
