VSR Collection - Vessel Stability Verification Software

NextGen integrates the historic VSR Collection (Verifiche di Stabilità dei Recipienti - Stability Verification of Vessels), the Italian technical standard issued by ISPESL (now INAIL) for the design and safety verification of pressure vessels.

This collection is essential for revamping activities and the recalculation of existing equipment in Italy. NextGen provides the formulas and calculation methods necessary for the structural verification of components subjected to internal and external pressure, ensuring operational continuity and compliance with original national regulations.

NextGen supports the following chapters of the VSR collection:

Technical Rules

  • VSR.0 - General provisions of the Collection
  • VSR.1.A - General provisions for the VSR.1 section
  • VSR.1.B - Determination of maximum allowable stress
  • VSR.1.C - Minimum wall thicknesses
  • VSR.1.D - Cylindrical shells under internal pressure
  • VSR.1.E - Dished heads
  • VSR.1.F - Conical heads and conical reducers under internal pressure
  • VSR.1.G - Spherical bodies under internal pressure
  • VSR.1.H - Components under external pressure
  • VSR.1.K - Openings and nozzles on walls under internal pressure
  • VSR.1.L - Flat walls and flat heads
  • VSR.1.M - Tubes
  • VSR.1.N - Heat exchanger tubesheets
  • VSR.1.P - Expansion joints
  • VSR.1.Q - Channels welded on the outer surface of pressure vessels
  • VSR.1.R - Bolts, tie rods and screws
  • VSR.1.U - Bolted flanged joints
  • VSR.2 - Pressure vessels made of austenitic stainless steels, nickel, titanium, zirconium and their alloys
  • VSR.3 - Pressure vessels made of cast iron
  • VSR.4 - Pressure vessels made of copper and its alloys
  • VSR.5 - Pressure vessels made of aluminium and its alloys

Additional verifications

When designing according to VSR, NextGen also supports the following verifications based on additional international standards:

  • Bolt tightening torque verification according to ASME PCC-1
  • Rectangular flanges according to PD 5500
  • Local loads verification according to WRC bulletins
  • Expansion joints verification according to EJMA
  • Structural analysis and lifting analysis for vertical vessels
  • Heat exchanger design according to TEMA
  • Direct import from HTRI Heat Exchanger Suite
  • Interface with Nozzle PRO for advanced nozzle load calculation