Abstract
Transient fluid loads in process piping have gained renewed focus recently with the design and construction of many LNG plants. The case of the shockwave (waterhammer) in piping following the rupture of a tube in a STHE has been well studied. Less attention has been paid to the high momentum slug flow which can occur when liquid slugs are accelerated in the piping by the gas.
This paper will examine some of the practical considerations for assessing the dynamic loads resulting from this high momentum slug flow. A method to obtain the force vector for any 3-dimensional change in direction will be presented. The use of DLFs for loads where a detailed time history profile is available will be discussed. The possibility of taking credit for simultaneously acting forces will be investigated.
The applicability of the B31.3 allowable stress for occasional loads will be examined and compared against advanced finite element models using shell elements.