Understanding Valve Sizes: Inches vs DN vs MM
Understanding Valve Sizes: Inches vs DN vs MM
Valves are essential components in various industries, regulating the flow of fluids within piping systems. When it comes to specifying valve sizes, three common metrics are often used: inches, DN (Diameter Nominal) and millimeters. While these all provide measurements for valve sizes, understanding the differences between them is crucial for accurate selection and installation.
Inches, as the name suggests, denote valve sizes in inches, measuring the diameter of the valve's opening. This system is widely used, especially in regions where imperial units are prevalent. On the other hand, DN is a metric system used to standardise pipe and valve sizes based on their nominal diameter in millimeters. DN sizes are part of the ISO (International Organisation for Standardisation) metric series and are commonly used in Europe and many other parts of the world. Finally millimeters are commonly used to measure valve sizes, providing precise measurements that are widely adopted in industries worldwide.
To help clarify the correspondence between these 3 sizing systems, below is a comparison table outlining the different valve sizes in inches, DN, and millimeters to help you navigate through the various standards more effectively:
Valve Size DN
(Diameter Nominal) | Valve Size Inches | Valve Size Millimeters |
| DN08 | 0.375" | 9.525mm |
| DN10 | 0.25" | 6.35mm |
| DN15 | 0.5" | 12.7mm |
| DN20 | 0.75" | 19.05mm |
| DN25 | 1" | 25.4mm |
| DN32 | 1.25" | 31.75mm |
| DN40 | 1.5" | 38.1mm |
| DN50 | 2" | 50.8mm |
| DN65 | 2.5" | 63.5mm |
| DN80 | 3" | 76.2mm |
| DN100 | 4" | 101.6mm |
| DN125 | 5" | 127mm |
| DN150 | 6" | 152.4mm |
| DN200 | 8" | 203.2mm |
| DN250 | 10" | 254mm |
| DN300 | 12" | 304.8mm |
| DN350 | 14" | 355.6mm |
| DN400 | 16" | 406.4mm |
| DN450 | 18" | 457.2mm |
| DN500 | 20" | 508mm |
| DN600 | 24" | 609.6mm |
Keep in mind that while these sizes may seem straightforward, there can still be variations depending on the valve type and specific industry standards. It's always advisable to consult with professionals or refer to the manufacturer's specifications to ensure compatibility and performance.
Understanding the different valve size standards will not only simplify the selection process but also ensure the optimal functioning of your systems.
