ISO 27509-2012 pdf free download

ISO 27509-2012 pdf free download.Petroleum and natural gas industries Compact flanged connections with IX seal ring
Industries du pOtrole et du gaz nature! — Raccordements a brides corn pactes avec bague d’étanchéité IX.
— They have been designed so that a static mode is maintained in the bolted joint up to 1,5 times the
specified pressure/temperature rating, see 7.2. Static mode Is maintained as long as the difference
between maximum and minimum nominal stress sustained by the bolts in the joint does not exceed 5 %
of the minimum values specified in Table 3.
— They have been standardized to cover as a minimum the same pressure temperature class designations and sizes as can be found in ASME B 16.5 with equal or better performance.
— They have been standardized to fit with commonly used standards by the valve industry (e.g. ASME B16.34, ISO 14313 and the EN 12516 series of parts), and other valve standards which make reference to these standards for pressure design.
— The weakest part of flanged connections according to this International Standard regarding fatigue failure is always located somewhere in the transition from flange to pipe or flange to nozzle neck of an equipment or valve. The bolted joint itself is never subjected to fatigue load if considerations to cycling temperatures are taken when selecting bolt material, see 6.3.
4.2 Design principles
Figure 1 shows the design principles of compact flanges and its seal system according to this International Standard.
The flange face includes a slightly convex bevel with the highest point, called the heel, adjacent to the bore and a small outer wedge around the outer diameter of the flange. The assembly is made up by tightening/tensioning the flange bolting which pulls the two connector halves together. The bevel angles have been standardized for different and relevant adjoining pipe wall thicknesses for each welding neck flange of a given size and pressure class.
For the IX seal ring, axial forces are exerted on the taper of the metal seal ring and translated into a radial sealing force. Furthermore with increased pre-load, the bevel is closed and face to face contact is achieved at the outer wedge while most of the bolt pre-load is transferred as compressive forces between the flange faces at the heel, as illustrated in Figure 1. The arrows in the figure indicate the applied forces/pressure and the contact forces after make-up and during normal operation.
The principle design of the flange face includes two independent seals. The first seal is created by application of seal seating stress at the flange heel. However, an undamaged flange heel may not seal at any extreme load condition, but the heel contact will be maintained for pressure values up to 1,5 times the flange pressure rating at room temperature for any combination of WN flange and a corresponding pipe within given limits of pipe wall thicknesses in tables of dimensions. This requirement is only applicable when the WN thickness fulfils the code requirement for minimum pipe wall thickness for the actual material. The main seal is the IX seal ring. The seal ring force is provided by the elastic stored energy in the stressed seal ring. Any heel leakage will give internal pressure acting on the seal ring inside intensifying the sealing action.ISO 27509-2012 pdf free download.