Separate size and pressure class
DN denotes nominal size and PN a reference pressure class. Neither permits unrestricted operation independent of temperature, material and fluid. Flanges with the same nominal size may use incompatible standards. Check DIN/EN or ASME Class, connection dimensions and pressure-temperature ratings in the manufacturer documents.
Isolation or control?
Ball, butterfly, globe, gate and check valves serve different functions. Isolation and precise flow control are different selection tasks. Control duty requires capacity, characteristic, noise, cavitation and actuator checks. A check valve is selected around reverse-flow prevention and closing behaviour.
Use Kv under the right conditions
Kv expresses capacity under defined reference conditions for water. For a simple liquid case, Q = Kv × √(Δp / SG), with Q in m³/h, differential pressure in bar and SG as relative density. Do not apply this directly to gas, steam, two-phase or cavitating flow. Share size, pressure class, fluid, temperature, connection and quantity.
Let’s select the right product.
Consider nominal size, pressure class, fluid, temperature, connection and actuation together. Refer to the technical catalogue for suitable materials and operating limits.