En 1092-1 Flange and DIN standard

Flanges can be made according to different standard,such as ASME,DIN,JIS standards.

DIN Flange standard,now known as EN 1092-1 for steel flanges,but previouly,it is DIN standard,like

EN 1092- 1 Standard

The standard EN 1092-1 was first published by CEN (European Committee for Standardization) in the year 2001.It is to replace the old DIN standard for flanges,

EN 1092 – 1 is a European standard titled “Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN designated – Part 1: Steel flanges”.

Scope of Application

It specifies requirements for circular steel flanges with nominal pressures (PN) ranging from PN 2.5 to PN 400 and nominal sizes (DN) from DN 10 to DN 4000. It is applicable in various industrial sectors such as chemical, petrochemical, food, pharmaceutical, oil and gas, power generation, and water treatment industries.

Main Contents

Flange Types and Seal Faces
- Different types of flanges and their seal face forms are defined. Common types include slip – on flanges (e.g., en 1092 – 1 type 01a, where “type 01” indicates a welded flange and “a” indicates a flat seal face) and loose – flanged flanges (e.g., en 1092 – 1 type 02a, where “type 02” indicates a loose – flanged flange). Different types are suitable for different pressure ratings and temperature conditions, and the seal face form significantly affects the performance of the joint.
Dimensions and Tolerances
- Dimensions of flanges such as outside diameter, inside diameter, thickness, and bolt hole spacing are specified, along with corresponding tolerance ranges, to ensure that flanges produced by different manufacturers can be mutually compatible

Carbon Steel (Non-alloy)

Carbon Steel (Non-alloy)
Material Grade	EN Equivalent	Old DIN	Use
P245GH	EN 10222-2	C22.8	General use in pressure vessels
P250GH	EN 10222-2	—	Slightly improved over P245GH
P265GH	EN 10222-2	—	Higher temperature/pressure service
S235JR / S275JR / S355JR	EN 10025	St37, St44, St52	Structural applications (low pressure)

Stainless Steel grade

Material Grade	EN Grade	ASTM Equivalent	Use
1.4301	X5CrNi18-10	AISI 304	General corrosion resistance
1.4307	X2CrNi18-9	AISI 304L	Low carbon version, for welding
1.4401	X5CrNiMo17-12-2	AISI 316	Higher corrosion resistance
1.4404	X2CrNiMo17-12-2	AISI 316L	Weldable, low carbon
1.4541	X6CrNiTi18-10	AISI 321	With titanium, for high temp stability

🔹 Alloy Steel

Material Grade	Material Standard	Use
16Mo3	EN 10028-2	High-temperature resistance, steam service
13CrMo4-5	EN 10222-2	High temp and pressure, especially in boilers
10CrMo9-10	EN 10222-2	For petrochemical and thermal plant use

Pressure and Temperature Ratings
- It uses the PN (Pressure Nominal) system for pressure classification of flanges. PN represents the maximum working pressure (in bar) that a flange can withstand under normal operating conditions. Different PN ratings correspond to different pressure and temperature – bearing capacities. It should be noted that this PN pressure rating system is unique to Europe and may be different from the pressure rating systems in other regions (such as ANSI/ASME or JIS standards).
Threads, Bolt Sizes, and Surface Treatment
- Thread specifications and bolt sizes for flange connections, as well as requirements for the surface finish of the flange seal face, are specified to ensure the tightness and reliability of the connection.
Marking
- Material designation (e.g., P245GH or 1.4301)
- Type number (e.g., Type 11 for weld neck flange)
- Pressure rating (e.g., PN16)
- Nominal size (e.g., DN100)
- Manufacturer’s mark and batch

Now Old DIN standard flanges are still using by many engineers,so it is important to understand the comparison of EN 1092-1 and old DIN standard flanges.Below you would find the mapping table.