Investigation of the Effects of Hydraulic Transient due to Instantaneous Valve Closure in a Petroleum Pipeline

Abstract

Pressure surge analysis of petroleum pipeline transporting
automotive gas oil (AGO) also known as Diesel oil was carried out in
this research work. Pressure transient analysis is often more
significant than the steady state analysis that engineers usually use in
pipeline design. Pressure transient analysis helps to understand the
additional pressures the pipeline can be subjected to as a result of
instantaneous rapid valve closures or pump failure. The fluid pressure
and flow rate in the pipeline system may change significantly at some
intervals of time due to the valve closure and such types of unsteady
situations are encountered more often in pipelines where the valves
are suddenly closed. In this paper, pressure surge due to
instantaneous valve closure in a petroleum pipeline conveying AGO
was studied in a virtual environment. WANDA Transient 4.5.1210
commercial software was used for the analysis of the pressure surge
in the pipeline due to instantaneous valve closure time of 4.75s. It was
observed in the study that pressure at some nodes rise significantly up
to about 1400 kPa against the initial inlet pressure of 120 kPa due to
the instantaneous valve closure and it drastically drops at some nodes
to negative pressure of about -100 kPa and hence the formation of
cavitations. The analysis showed that the magnitude of the pressure
surge decreases as the valve closure is increased.