What is Emergency Shutdown System (ESD)?
Emergency Shutdown is an emergency shut down, due to the failure of the supply utility or due to the failure of important components in the plant (such as pump feed failure, reactant supply failure, or furnace failure, etc.).
An Emergency Shutdown System is a method for stopping process operations and isolating from incoming connections or currents to reduce the possibility of an unwanted event quickly.
The purpose of the ESD system is to protect personnel, be able to protect facilities, and prevent environmental impacts from process activities. The ESD system is considered as one of the main security systems that can be provided for any facility.
Emergency Shut Down is a minimum requirement or procedure that must be accepted in carrying out the design, manufacturing and testing of wireline equipment and requirements related to aspects of safety, occupational health, and the oil, gas and geothermal industry environment.
Fail safe system in ESD:
ESD system design is usually based on the independence of fail-safe component utilization. The fail-safe feature is obtained by ensuring that the component selected in the ESD system is during a failure of the process component to switch to a condition that is considered “safe”.
ail-safe is usually referred to as de-energized because the impact on inputs, outputs, cables, utility supplies or component functions must de-energize against the end result that allows the safety device to fail again in its safe mode.
Fail-safe specifications for valves can be achieved by Failing Close (FC), Failing Open (FO) or Failing Stable (FS).
The use of steady fail safe mode allows detected failures to occur except for additional instrumentation in the ESD system components.
Activation points for ESD systems:
The following guidelines provide several features that must be considered.
The activation point must be placed at least 8 meters (25 ft.) From a high process from the hazard location but not more than 5 minutes from any location in the facility.
The location chosen must be more against the wind.
They must be near other emergency devices that may need direct activation in an emergency.
Main access to the affected area must not be disturbed. The location of the activation point can be accessed by the vehicle or maintenance will affect the operation and cause the device to be relocated or damaged.
The activation point must be installed at a height that is comfortable for personnel and ergonomic.
The control room must always be provided with an ESD activation point located on the main control so that it is easily accessed by the operator.
Alarm system for ESD:
In the ESD system, there are several signals that must be considered, namely the first alarm, the second alarm. This signal is activated based on a work area called the flange area. This area has a radius of 1 m.
If the Loading arm is outside the flange area, the pre-alarm signal will be active and this will be an early warning for the operator. If this arm continues to move outside the work area with an area of 4m² then the alarm signal 1.
Under this condition ESD 1 will work by stopping the gas distribution process. Currently the operator must control the arm to its original position. If the arm continues to move and the operator has not had the chance to improve the position, then ESD 2 will be activated by removing the connection with the valve installed on the tanker (Emergency Disconnection).