Page 454 - Offshore Electrical Engineering Manual

Preparation and Use of Performance Standards 441

INSTALLATION: PERFORMANCE STANDARD: EMERGENCY SHUTDOWN SYSTEM (cont.)
Functions Element Assurance
5 To provide ESD Level 0 - a) The ESD Level 0 (Catastrophic Shutdown) logic functions Functional Design
Catastrophic Shutdown. shall operate as specified on the cause and effect diagrams to Specification for
shut down systems. Emergency Shutdown
System
Function test Category 1
logic functions against a
sample from the cause and
The causes and effects of a catastrophic platform shutdown shall be effect chart.
as described in the installation safety case. ReferenceESD
Maintenance Routines
6 To provide safety systems on a) PA/GA systems shall remain operational on a level 0 ESD. Functional Design
activation of ESD at level 0. b) The diesel firewater pumps would remain operational until the Specification for
diesel day tank is empty on a level 0 ESD. Emergency Shutdown
c) The forward and aft thrusters will run for over 3 hours under System
Heading Control System control to allow for safe evacuation on
a level 0 ESD. a) See PA/GA performance
d) All battery backed emergency lighting shall remain operational. standard
e) Navigational aids shall remain operational b) See Active Fire
Protection performance
Only emergency systems with a self-contained Ex ‘d’ -protected standard
built-in power supply shall be left operational. c) See Heading Control
performance standard
d) See Escape Lighting
performance standard e)
See Navaids performance
standard
7 To isolate all hydrocarbon a) A level 1 shutdown will close all ESD valves, and Functional Design
sources including the FPSO automatically open blowdown valves in the affected area only Specification Section 3
hydrocarbon pipelines. if initiated by fire or gas detection. Emergency Shutdown
System
Function test against ESD
level 1 Cause & Effect
Chart
The ESDVs on the hydrocarbon lines are designed and located in
accordance with Pipeline Safety Regulations SI 825 (1996)
8 To provide means to initiate a) A level 2 Shutdown can be initiated by Operator intervention Functional Design
ESD in the control room. via Manual Pushbuttons in the Control Room and selected Specification for
plant areas. Emergency Shutdown
System
b) A level 1 shutdown shall be activated by a Manual Emergency Function test logic
Pushbutton in the control room or automatically if a gas functions against a sample
release or fire occurs. from the cause and effect
chart. ReferenceESD
c) A level 0 shutdown shall be initiated manually from the Maintenance Routines.
control room or from manual stations strategically located
around the installation.
9 To provide accurate feedback The Process Control Operator Stations include the facility to Functional Design
of ESD functions to the control interface with the ESD system. It is possible to read the status of the Specification for
room. ESD Inputs and Outputs and the system status from any window. Emergency Shutdown
System
a) Category 1 ESD system input status, output status and
sequence of events initiating and following a trip. Function test logic
functions against a sample
c) All the Operator actions, system alarms, system input and from the cause and effect
system output status within the plant. chart. ReferenceESD
Maintenance Routines.
FIGURE 9.2.1, cont’d