ASME B31.8 has clear definition provided in Para 833.1 as
1. Piping in which soil or supports prevent axial displacement of flexure at bend in "Restrained" which can have straight section of buried piping or bends /pipe in stiff soil.
2. Piping that is freed to displace axially or flex at bends...
My experience says that the buried pipe should be modelled till virtual anchor lenght in a software... some times we model twice of the virtual anchor length. Virtual anchor length can be calculatd by hand calculations.
However client is asking us to model 10 km long pipeline in CAESAR II. When...
Problem:A pipe is connected to pump creating 13 bar pressure (shut off pressure 17 bar) has ESD valve at 3.5km distance.Flow velocity is 6 ft/sec. Valve closure Time is 4.5 seconds. The Pipe size is 28 inch. As per Joukowsky equation the surge force comes out to be above 200Tonnes. The above...
