--- title: What Are the Different Types of PN Flanges? date: 2025-06-27T01:18:22Z modified: 2026-07-16T07:20:51Z permalink: "https://www.longanflange.com/blog/what-are-the-different-types-of-pn-flanges/" type: post status: publish excerpt: "" wpid: 2839 categories: - Blog featured_image: "https://www.longanflange.com/wp-content/uploads/2025/07/What-Do-DN-and-PN-Mean-on-Flanges.webp" timestamp: 2026-07-16T07:20:51Z tags: - Blog --- When choosing metric flanges for your piping system, it’s important to know: what are the different types of PN flanges? PN (Pressure Nominal) flanges are defined by pressure class (e.g., PN6, PN10, PN16) and standardized dimensions under EN/DIN/ISO norms. They’re widely used in water, HVAC, and industrial applications across Asia, Europe, and beyond. ## **What the “PN” Rating Means** “PN” stands for nominal pressure, expressed in bars. For example, a PN16 flange is rated for a maximum of 16 bar (~232 psi). These flanges are sized under EN 1092-1 (formerly DIN 2501) and ISO 7005, ensuring bolt patterns, diameters, and thickness meet international requirements. ## **Common PN Types and Where They’re Used** PN flanges are categorized by pressure class, with each level suited to different system demands. Here’s how the most common types break down and where they’re typically applied: - **PN6** is used in low-pressure pipelines such as irrigation, basic drainage, and gravity-fed systems. It’s a fit for non-critical, low-flow installations. - **PN10** supports moderate pressure and is often found in municipal water distribution, HVAC loops, and compressed air systems. - **PN16** is the most widely used across industries. It handles pressures up to 16 bar and is ideal for water, gas, and basic chemical transport. - **PN25 and PN40** flanges are suited for systems operating at higher pressures, such as steam service, industrial cleaning lines, or heavy-duty plant piping. - **PN64 and above** are specialized flanges designed for power generation, heavy chemical processing, or hydraulic systems operating at extreme pressures. ![Plate Flanges](https://www.longanflange.com/wp-content/uploads/2024/10/a80020c8c01b291afa28-1.png) Plate flanges Plate flange is the most common flange, the pressure is PN2.5, PN6, PN10, PN16, PN25. [Inquiry Now](https://www.longanflange.com/products/plate-flange/) ## **PN Flange Types: Face and Connection Styles** Beyond pressure rating, PN flanges also vary in face style and connection type—both of which affect how they’re installed and sealed in a pipeline. - **Weld neck PN flanges** have a sloped hub that connects directly to the pipe, helping to spread stress evenly and reinforce the joint. This makes them ideal for high-stress environments where shock, vibration, or temperature changes are common. - **Slip-on and socket weld types** are often used in lower-cost setups and are commonly applied in compact or lower-capacity pipelines. They’re easier to align during installation and work well up to PN40 pressure classes. - **Blind flanges** are solid plates used to close off a pipeline or pressure vessel. They’re common at inspection points or system ends. - **Lap-Joint flanges** are used with a stub end and are ideal for systems where disassembly or realignment is frequent. - **Threaded, reducing, and expanding PN flanges** are also available for specialized systems, especially when transitions between sizes or fittings are needed. ## PN Flanges vs ASME Flanges PN flanges follow EN 1092-1 standard and use metric pressure units (bar), while ASME flanges follow B16.5 standard and use pressure classes (psi). | Feature | PN Flanges (EN/DIN) | ASME Flanges | | --- | --- | --- | | Pressure Unit | Bar | PSI | | Standard | EN 1092-1 / DIN | ASME B16.5 | | Common Ratings | PN10 / PN16 / PN25 | Class 150 / 300 / 600 | | System Type | Metric system | Imperial system | | Compatibility | Limited with ASME | Limited with PN | Key takeaway: PN and ASME flanges are NOT directly interchangeable without engineering verification. ## **What to Know When Buying PN Flanges** Choosing the right PN flange goes beyond just matching the pressure class. Keep the following factors in mind when selecting a PN flange: - **Material selection is key**. You can source PN flanges in various materials, including stainless steel, carbon steel, and specialty metals depending on the application. For example,[ stainless steel PN flanges](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/stainless-steel-flange.md) are preferred in corrosive or hygienic environments like food, pharma, and water treatment. - **Make sure it meets the correct standard**. PN flanges should conform to EN 1092-1. If you’re integrating with an ANSI system, check if[ ASME flanges](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/asme-flange.md) are more appropriate to avoid fitment issues. - **Always factor in pressure margin**. Don’t choose a flange that matches your exact operating pressure—build in some safety headroom to extend flange life and avoid performance drops. ## How to Choose the Right PN Flange Instead of selecting by pressure alone, engineers should consider: ### 1. Operating Pressure + Safety Margin Always select a PN rating higher than actual working pressure. ### 2. Medium Type - Water → PN10 / PN16 - Steam → PN25 / PN40 - Chemicals → Stainless steel PN flanges ### 3. Temperature Conditions Higher temperature reduces allowable pressure rating. ### 4. Standard Compatibility Ensure compliance with EN 1092-1 or matching system standard. Result: correct sealing performance + longer service life. Need Stainless Steel Flanges for Your Project? Manufacturer since 2011 · Exported to 50+ countries · SS304, 316L, duplex 2205 & 2507 · Up to DN4000 · ASME, DIN, GOST & JIS · ISO 9001 & PED certified · MOQ 1 piece · Quote within 24 hours [Get a Factory-Direct Quote →](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/contact.md) ## **What Are the Different Types of PN Flanges: Conclusion** The different types of PN flanges are defined by pressure rating (PN6 to PN100+), face type (weld-neck, slip-on, blind, etc.), and compliance with EN 1092-1 standards. Matching flange type, pressure class, and material to your system ensures a reliable seal and lasting performance. Need help selecting the right PN flange? [Longan Flange](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/about.md) stocks certified stainless and alloy options, ready to meet your industrial, chemical, or water system needs. [Contact us](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/contact.md) right now for more info! ## Frequently Asked Questions About PN Flanges ### What are the 6 types of flanges? PN flanges include Weld Neck, Slip-On, Blind, Lap Joint, Socket Weld, and Threaded types. --- ### Are PN10 and PN16 the same? No. PN10 is rated for 10 bar pressure, while PN16 is rated for 16 bar. They differ in thickness and application. --- ### What are PN10, PN16, and PN25 standards? They are pressure classes under EN 1092-1 standard, indicating maximum working pressure in bar at 20°C. --- ### Are PN16 and PN40 flanges the same? No. PN40 is designed for much higher pressure systems and has thicker flange construction. [Get a Quote](https://www.longanflange.com/wp-content/uploads/wp-mfa-exports/page/contact.md)