Engineering guide
The EFLA module provides the dimension tables for circular steel flanges to DIN EN 1092-1. If you want to select a circular flange by nominal pressure and nominal size, you get all the geometric characteristics here: outside diameter, bolt circle diameter, bore diameter, flange thickness, raised face dimensions, and the number, diameter and thread of the bolt holes. This lets you specify flange joints in vessel and piping design quickly and in line with the standard, without having to search the extensive tables of the standard by hand.
The edition stored here, DIN EN 1092-1:2002-05, has been withdrawn and superseded by later editions of DIN EN 1092-1 (currently the 2018 edition with amendments). For existing plants, spare-part procurement and re-rating of older equipment, however, the 2002-05 edition remains relevant, because flanges built at the time were manufactured to exactly these table values. For new designs, the current edition of the standard should always be consulted and the dimensions cross-checked.
Typical applications are the selection of weld-neck flanges, blind flanges, loose (lap-joint) flanges or threaded flanges (flange type) for pressure ratings from PN 2.5 to PN 400. The table values also serve as input data for strength calculations of the flange joint, for example to EN 1591-1 or EN 13445-3.
Scope
- Circular steel flanges
Typical workflow
Select the flange type
First, the flange type to DIN EN 1092-1 is chosen, for example weld-neck flange (type 11), plate flange, loose flange with collar, or blind flange. The type determines which dimension tables of the standard govern.
Define nominal pressure and nominal size
Nominal pressure (PN rating) and nominal size (DN) address the specific table row. Both quantities follow from the operating conditions of the pipe or vessel nozzle and from the pressure-temperature rating of the flange material.
Read off the main dimensions
The module returns the outside diameter, bolt circle diameter, bore diameter and flange thickness of the selected flange. These dimensions define the mating geometry and must match the companion flange.
Determine raised face and bolting
In addition, the outside diameter and height of the raised face (facing type, e.g. type B) as well as the bolt hole diameter, number of holes and the associated thread are output. This fully defines the gasket selection and the bolt order.
Carry over into further calculations
The dimensions obtained can be used as input data for leak-tightness and strength calculations of the flange joint, for example to EN 1591-1 or EN 13445-3 clause 11.
Frequently asked questions
Is DIN EN 1092-1:2002-05 still valid?
No, the 2002-05 edition has been withdrawn. The standard has been revised several times; DIN EN 1092-1:2018 with later amendments is currently in force. The flange dimensions have remained largely stable across the editions, but there have been detailed changes to facing types, material assignments and pressure-temperature tables. For re-rating existing flanges, the edition valid at the time of construction is the correct reference; for new designs, the current one.
Does selecting a flange from the DIN EN 1092-1 tables replace a strength calculation of the flange joint?
Within the pressure-temperature rating of the standard, standardized flanges are considered adequately dimensioned, provided the material, gasket and bolting comply with the specifications. For additional external loads (piping forces and moments), special leak-tightness requirements or non-standard gaskets, an additional calculated verification, e.g. to EN 1591-1, is required.
What is the raised face (type B), and when do I need other facing types?
The raised face is the machined, raised sealing surface of the flange; its dimensions (outside diameter and height) are specified in the standard. For higher leak-tightness requirements or special gaskets, DIN EN 1092-1 provides further facing types, such as tongue and groove (type C/D) or spigot and recess (type E/F). The choice of facing type must be consistent between flange, companion flange and gasket.
Are DIN EN 1092-1 flanges compatible with ASME B16.5 flanges?
No. The bolt circles, numbers of holes, flange thicknesses and facings of the EN PN series and the ASME class series differ; the two systems cannot be bolted together. In plants mixing both standards, transition pieces or special flanges verified for the specific project must be used.
Technical content source: LV-Solved-Problems-Content 628d313247e7