The purpose of a production platform surface safety system is to protect personnel, the environment, and the facility from threats to safety caused by the production process. The purpose of a safety analysis is to identify undesirable events that might pose a threat, and define reliable protective measures that will prevent such events or minimize their effects if they occur.

The safety flow chart is a chart depicting the manner in which undesirable events could result in personnel injury, pollution, or facility damage. It also shows where safety devices and procedures should be used to prevent the propagation of undesirable events. As shown on the chart, (see API-RP-14-C) the release of hydrocarbons is a factor in virtually all threats to safety. Thus, the major objective of the safety system should be to prevent the release of hydrocarbons from the process and to minimize the adverse effects of such releases if they occur.

The overall objectives may be enumerated as follows:

• Prevent undesirable events that could lead to a release of hydrocarbons.
• Shut in process or affected part of the process to stop the flow of hydrocarbons to a leak or if overflow occurs.
• Accumulate and recover hydrocarbon liquids and disperse gases that escape from the process.
• Prevent ignition of released hydrocarbons.
• Shut in the process in case of fire.
• Prevent undesirable events that could cause the release of hydrocarbons from equipment other than that in which the event occurs.

The operating of the safety system should be (a) automatic monitoring and automatic protective action if an abnormal condition indicating an undesirable event can be detected by a sensor, (b) automatic protective action if manually actuated by personnel, and (c) continuous protection by support systems that minimize the effects of escaping hydrocarbons.

The recommended analysis and design procedures for a platform safety system are based on the following premises:

• Designed for safe operation in accordance with good engineering practices.
• The safety system should provide two levels of protection to prevent or minimize the effects of an equipment failure within the process.
• The two levels of protection should be the highest order (primary) and the next highest order (secondary) available.
• The use of proven analysis techniques, adapted to the production process, will determine the minimum safety requirements for a process component.
• All process components on a production platform comprise the entire process from the well head to the most downstream discharge point.
• When fully protected process components are combined into a facility, no additional threats to safety are created.
• The analysis procedure should provide a standard method to develop a safety system and provide supporting documentation.