BS EN 1591-1:2001+A1:2009 Flanges and their joints

Design rules for gasketed circular flange connections. Calculation method
BS EN 1591-1 defines a Calculation method for bolted, gasketed, circular flange joints. Its purpose is to ensure structural integrity and control of leak tightness. Where permitted, the Calculation method is an alternative to design validation by other means e.g.
– Special testing;
– Proven practice;
– Use of standard flanges within permitted conditions.

Example of flange calculation method (rollover to zoom)

Contents of BS EN 1591-1:

• Foreword
• Scope
• General
• Requirement for use of the Calculation method
• Validity
• Normative references
• Notation
• Use of figures
• Subscripts and special marks
• Symbols
• Terminology
• Calculation parameters
• Flange parameters
• Bolt parameters
• Gasket parameters
• Internal forces (in the joint)
• Applied loads
• Compliance of the joint
• Minimum forces necessary for the gasket
• Internal forces in assembly condition (I = 0)
• Internal forces in subsequent conditions (I = 1, 2, …)
• Checking of the admissibility of the load ratio
• Bolts
• Gasket
• Integral flange and collar
• Blank flange
• Loose flange with collar
• Requirement for limitation of non-uniformity of gasket stress
• Dimensions of standard metric bolts
• Scatter of bolting-up methods
• Assembly using torque wrench
• Flange rotations
• General
• Use of flange rotation
• Calculation of flange rotations
• Diagram of calculation sequence
• Joints with spacer-seated flanges
• Introduction
• Behaviour of spacer-seated gaskets
• Simplified treatment
• Use of the former creep factor gC
• Relationship between this European Standard and the Essential
• Requirements of EU Directive 97/23/EC