API RP 14C:2001(2007) pdf download

API RP 14C:2001(2007) pdf download.Recommended Practice for Analysis, Design, Installation, and
Testing of Basic Surface Safety Systems for Offshore Production Platforms.
d. All safety devices shown in the figures in Appendix A for each component would be considered and would be installed unless conditions exist whereby the function normally performed by a safety device is not required or is performed adequately by another safety devicets). The Safety Analysis Checklists (SACS) in Appendix A list equwalent protection methods, thereby allowing the exclusion of some devices.
e. If a process component is used that is not covered in Appendix A. an SAT for that component would he developed as discussed in (a) and (b) above.
4.2.3 Protective Shut-In Action
When an abnormal condition is detected in a process component by a safety device or by personnel, all input sources of process fluids, heat, and fuel should be shut off or diverted to other components where the) can be safely handled. If shutoff is selected, process inputs should be shut off at the primary source of energy (wells, pump, compressor. etc.). It is not advisable to close the process inlet to a component if this could create an abnormal condition in the upstream component, causing its safety devices to shut it in. This would be repeated for each component back through the process until the primary source is shut in. Each component would therefore be subjected to abnormal conditions and must be protected by its safety devices every time a downsiream component shuts in. This cascading effect depends on the operation of several additional safety devices and may place undue stress on the equipment.
a. It may be desirable to shut in the inlet to a process component for additional protection or to prevent upstreani components from equalizing pressure or liquid levels after the primary source is shut in. If this is desirable, the primary source of energy should be shut in simultaneously with or prior to closing of the component inlet valve.
b. There may be special cases where shut in by cascading is acceptable. As examples:
I. The source of input to a separator is frequently changed as wells arc periodically switched into the separator. If the well(s) producing to the separator is to be directly shut in shen an abnormal condition is detected, the safety system logic must be changed each time different wells are switched into the unit, This creates the possibility of oversight in changing the logic. In this case, it may be preferable to close the separator inlet, and let the resulting high flowline pressure cause the well(s) to shut in by action of the flow line PSH sensor, The header and the flow line should be rated frr the masimum pressure thai could be caused by this action.
2. A platform receives pcoduction through a flow line from a satellite well. Although the source of energy to the system is the satellite well. dctcction of an abnonnal condition on the platform should cause activation of an SDV on the incoming flow line. If it is desired to shut in the satellite well Ibllowing closure of the flow line SDV at the platform. this may be accomplished by usc of a flow line PSH sensor installed at the satellite location.
3. A compressor installation is equipped with an automatic divert valve that permits production to he maintained from wells capable of producing against pipeline pressure hen a compressor shut down occurs. In this case, wells incapable of producing against pipeline pressure may be shut in by action of the individual flow line PSH sensors to minimize potential safety system logic problems as discussed in (a) above.