BS EN 1591-1:2013
$215.11
Flanges and their joints. Design rules for gasketed circular flange connections – Calculation
| Published By | Publication Date | Number of Pages |
| BSI | 2013 | 80 |
This European Standard defines a calculation method for bolted, gasketed, circular flange joints. Its purpose is to ensure structural integrity and control of leak tightness. It uses gasket parameters based on definitions and test methods specified in EN 13555.
The calculation method is not applicable to joints with a metallic contact out of the sealing face or to joints whose rigidity varies appreciably across gasket width. For gaskets in incompressible materials, which permit large deformations, the results given by the calculation method can be excessively conservative (i.e. required bolting load too high, allowable pressure of the fluid too low, required flange thickness too large, etc.).
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | Contents Page |
| 7 | Foreword |
| 9 | 1 Scope 2 Normative references 3 Notation 3.1 Use of figures 3.2 Subscripts and special marks 3.2.1 Subscripts |
| 11 | 3.2.2 Special marks 3.3 Symbols |
| 16 | 3.4 Terminology 3.4.1 Flanges 3.4.2 Loading 3.4.3 Load conditions 3.4.4 Compliances |
| 24 | 4 Requirements for use of the calculation method 4.1 General 4.2 Geometry |
| 25 | 4.3 Material 4.4 Loads 5 Checking the assembly for a specified initial tightening bolt force (or torque) |
| 26 | 6 Calculation parameters 6.1 General 6.2 Flange parameters 6.2.1 General |
| 27 | 6.2.2 Flange ring 6.2.2.1 Bolt holes 6.2.2.2 Effective dimensions of flange ring |
| 28 | 6.2.3 Connected shell 6.2.3.1 Flange with tapered hub 6.2.3.2 Flange without hub 6.2.3.3 Blank flange |
| 29 | 6.2.3.4 Collar 6.2.4 Flexibility-related flange parameters 6.2.4.1 Integral flange and collar 6.2.4.2 Blank flange |
| 30 | 6.2.4.3 Loose flange with collar 6.3 Bolt and washer parameters 6.3.1 General 6.3.2 Effective cross-section area of bolts 6.3.3 Flexibility modulus of bolts 6.3.4 Geometric parameters for washers and contact surfaces 6.3.4.1 Absence of washers 6.3.4.2 Presence of washers |
| 31 | 6.3.5 Flexibility modulus of washers 6.4 Gasket parameters 6.4.1 General 6.4.2 Theoretical dimensions 6.4.3 Effective dimensions |
| 32 | 6.4.4 Axial flexibility modulus of gasket |
| 34 | 6.4.5 Lever arms 6.4.5.1 All flanges 6.4.5.2 Integral flange and collar 6.4.5.3 Blank flange 6.4.5.4 Integral flange and blank flange 6.4.5.5 Loose flange with collar |
| 35 | 7 Forces 7.1 General 7.2 Applied loads 7.2.1 Assembly condition (I = 0) 7.2.2 Subsequent conditions (I = 1, 2 …) 7.2.2.1 Fluid pressure 7.2.2.2 Additional external loads |
| 36 | 7.2.2.3 Thermal loads 7.3 Compliance of the joint |
| 37 | 7.4 Minimum forces necessary for the gasket 7.4.1 Assembly condition (I = 0) 7.4.2 Subsequent conditions (I = 1, 2, ….) 7.5 Internal forces in assembly condition (I = 0) 7.5.1 Required forces |
| 38 | 7.5.2 Accounting for bolt-load scatter at assembly |
| 39 | 7.6 Internal forces in subsequent conditions (I = 1, 2, …) |
| 40 | 8 Load limits 8.1 General 8.2 Bolts |
| 41 | 8.3 Gasket 8.4 Integral flange and collar |
| 43 | 8.5 Blank flange |
| 44 | 8.6 Loose flange with collar |
| 45 | Annex A (informative) Dimensions of standard metric bolts |
| 46 | Annex B (informative) Tightening B.1 Scatter of initial bolt load of a single bolt — Indicative values ε1- and ε1+ for a single bolt B.2 Scatter for the global load of all the bolts |
| 47 | B.3 Manual uncontrolled tightening B.4 Assembly using torque wrench |
| 48 | B.5 Assembly using bolt tensioner |
| 50 | Annex C (informative) Flange rotations C.1 General C.2 Use of flange rotation C.3 Calculation of flange rotations |
| 52 | Annex D (informative) Use of the calculation method D.1 Calculation method principle |
| 53 | D.2 Mechanical model |
| 54 | D.3 Required checks D.4 Calculation sequence |
| 56 | Annex E (informative) Gasket/flange face friction coefficients examples |
| 57 | Annex F (normative) Determination of eGc,I based on a given PQR F.1 Determination of the deflection occurring during a PQR test |
| 58 | F.2 Determination of the deflection to be taken into account in the calculation |
| 59 | Annex G (informative) Sealing gasket parameter when no leakage rate is specified |
| 60 | Annex H (informative) Alternative calculation procedure taking into account the plastic deformation of the gasket in subsequent load conditions procedures (after assembly) H.1 Introduction H.2 Calculation procedure H.2.1 General description |
| 61 | H.2.2 No additional plastic deformation H.2.3 Additional plastic deformation H.3 Flat gaskets H.3.1 Flat gaskets with small or median deformations H.3.1.1 Basic formulae |
| 62 | H.3.1.2 Calculations for a general material law H.3.1.3 Calculations for a simplified material law |
| 63 | H.3.2 Flat gaskets with greater deformations |
| 64 | H.4 Metal gaskets with curved surfaces (Figures 3b, c, e, f ) H.5 Metal gaskets with octagonal section (Figure 3d) |
| 65 | Annex I (informative) Available, incomplete models for conversion of the leakage rates in different conditions (based on certain flow models) I.1 Introduction and warning I.2 Flow theory fundamentals I.2.1 Transport modes |
| 66 | I.2.2 Case of gases I.2.2.1 Parallel capillary model I.2.2.2 Dusty gas model |
| 67 | I.2.3 Case of liquids: Parallel capillary model I.3 Factors of influence on the leakage rate of gaskets and gasketed joints I.3.1 List of identified factors I.3.2 Limits and restriction of the proposed models |
| 68 | I.3.3 Dependence on pressure I.3.3.1 General I.3.3.2 Definition I.3.3.3 Molecular flow I.3.3.4 Visco-laminar flow I.3.3.5 Practical use |
| 69 | I.3.4 Dependence on temperature I.3.4.1 General I.3.4.2 Definition I.3.4.3 Molecular flow I.3.4.4 Visco-laminar flow I.3.4.5 Practical use |
| 70 | I.3.5 Dependence on the type of fluid I.3.5.1 General I.3.5.2 Definition I.3.5.3 Molecular flow I.3.5.4 Visco-laminar flow I.3.5.5 Practical use I.3.6 Influence of the gasket thickness |
| 71 | I.3.7 Influence of gasket width I.3.8 Influence of gasket stress I.3.9 Influence of other factors |
| 72 | I.3.10 Conclusion on the factors of influence I.4 Practical application for EN 1591-1 calculations I.4.1 General |
| 73 | I.4.2 Determination of a trend for the leakage rate for the flange connection in “actual” from “reference” conditions |
| 74 | I.4.3 Determination of a trend for the leakage rate for the flange connection in “reference” from “actual” conditions |
| 76 | Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Directive 97/23/EC |
| 77 | Bibliography |
