DN indicates the valve diameter, and PN indicates the pressure rating. For the correct selection, DN/PN should be evaluated together according to the line diameter and operating pressure. [Detailed content]

Ball valves are preferred for on/off applications; butterfly valves are advantageous for large diameters and when rapid on/off is required. The choice is made according to the line diameter, pressure, and intended use. [Detailed content]

For small diameters, threaded connections are practical and economical. Where higher pressure, larger diameters, or ease of maintenance are required, flanged connections are preferable.

The PN rating indicates the nominal pressure class that the valve can withstand. As pressure increases, the PN class must also increase; selecting the appropriate PN for the application is critical for safety and service life.

Globe valves are preferred in lines requiring flow rate adjustment/precise control (for control purposes). For simple on/off operation, a ball/butterfly valve is generally sufficient. [Detailed content]

The on/off valve completely opens or closes the flow. The control valve, on the other hand, provides flow rate/pressure control by adjusting the flow incrementally.

Check valves prevent backflow. They are used at pump outlets, booster pump systems, and lines where backflow is a problem.

It protects equipment such as valves, meters, and pumps by trapping sediment and particles in the pipeline. It is especially recommended before control valves and sensitive equipment.

Brass is common in water/heating systems; cast iron/steel is preferred in industrial and high-strength lines; and stainless steel is preferred in environments with a high risk of corrosion.

For some valve types (check valves, globe valves, filters, etc.), the flow direction is critical. The arrow indicating the flow direction on the product should be taken into consideration.

This depends on the PN rating of the product (e.g., PN16, PN40). The appropriate PN should be selected according to the operating pressure of the application.

For steam lines, a valve suitable for the application is selected that can withstand the required temperature and pressure. We can offer support and suggestions based on the operating conditions of the line.

Yes. Astel Mechanical Installation sells valve group products; we sell and ship throughout Türkiye, primarily from Bursa/Nilüfer. You can contact us for product selection and stock information.