pipelinermike
Mechanical
- Jul 30, 2003
- 8
A pipeline is installed in 3300 ft water depths (1467 psi external pressure) in a void state, i.e. internal pressure is zero. The pipeline is unburied - laying on bottom and there is a riser to the surface on one end.
The following have been proposed:
1. Pressure expansion (end cap, Bourdon, etc) occurs only when the internal pressure exceeds the external pressure. When the internal pressure is less than ambient, e.g.
during flooding or filling, the pipeline would contract as described by the Poisson effect.
2. Pressure expansion occurs at any point from the initial, void state. The hoop stress, and consequently
equivalent stress, would have to be re-calculated to account for the external pressure.
This is a most critical decision for us, therefore please include references to any text, papers, etc. with your reply if you have them.
The following have been proposed:
1. Pressure expansion (end cap, Bourdon, etc) occurs only when the internal pressure exceeds the external pressure. When the internal pressure is less than ambient, e.g.
during flooding or filling, the pipeline would contract as described by the Poisson effect.
2. Pressure expansion occurs at any point from the initial, void state. The hoop stress, and consequently
equivalent stress, would have to be re-calculated to account for the external pressure.
This is a most critical decision for us, therefore please include references to any text, papers, etc. with your reply if you have them.
