ESD system

ESD system protects against the possibility of a process excursion on topsides process plant developing into an incident (e.g. loss of containment), and to respond to emergency situations detected by other safeguarding fa-cilities. This protection is part of a hierarchy provided by a number of layers, typically: (i) Process control, including operator interven-tion via alarm functions; (ii) Instrument trip and ESD functions; (iii) Self acting mechanical protection such as relief valves or bursting discs. ESD and related instrumented trip functions are regarded as the primary automatic safeguard-ing function and mechanical devices are regarded as secondary protection in the sense that they act after the primary safeguard, though mechanical devices provide a fundamental or ultimate safeguard. The ESD system works by interpreting a number of input signals from plant measurements, and executing a cause and effect logic to shut down, isolate or vent redetermined items of plant, or to initiate safety systems, according to the nature, location and severity of any hazard. Manual inputs to the system are provided so that installation personnel may shut down the plant in response to conditions not covered by automatic protection.Advantages of KTC ESD SystemKTC ESD System ensures the safe production, processing, ... and other dealing with flammable substances:Prevents the uncontrolled release of flammable or explosive substances Prevents the unwanted or unnecessary accumulation of combustible flammable or explosive substancesDetecting all defines events which may require an emergency response Giving warning of an emergency Appropriate measurement with a view to limiting the extent of an emergency, including fire and explosionAppropriate measures with a view to protecting person on the installation during an emergency from the effects of fire and explosion.Providing Emergency Shutdown initiated from a control point. Due to importance of an Emergency Shutdown System in a plant KTC offers its solution as KTC ESD System, fundamentally based on a full redundant programmable safety system provided by PILZ Germany who is called PSS3000 which fully complies SIL3, AK6. ESD System features Some of the main features of KTC ESD System are as follow:1. Complying all requirements of Safety Integrity Level (SIL) 3. Modulating control systems to contain normal process deviations, operator intervention to maintain safe and effective production. 2. Capability of execution inter-trips from other systems, most obviously the fire & gas detection System and DCS by implementing similar 'cause and effect'logic3. It is designed to implement the process safety intent and perform with the highest availability and survivability. 4. Fully reliable Self-revealing of internal failures in dormant mode and in normal service 5. ESD function logic is generated from the overall process design and safety studies, and traditionally is expressed in a matrix which relates causes (e.g. sensor inputs) to effects (e.g. valve closures).6. Capability of defining several levels of shut down related to the nature of hazard. Depending on the complexity of the plant and the location the nature of the cause, more widespread shut downs can be defined. As an example for an Oil and Gas Plant the following levels can be defined: Process shutdowns Unit shut down Train shut down Production shutdown (with no blow down) Production shutdown (with blow down) Platform shutdown (with power generation shut down) Abandon platform shutdown (with complete electrical isolation) MINIMUM PROVISION OF ESD FUNCTIONS The minimum provision of ESD functions that are provided on a typical offshore oil and gas plant are as follow:All sections of a pressure system with a credible connection to a source of pressure Process vessels which contain liquid levels should have high and/or low trips on the level Compressors Fired vessels Pumps Shell-tube heat exchanger MINIMUM PROVISION OF ESD FUNCTIONS The minimum provision of ESD functions that are provided on a typical offshore oil and gas plant are as follow:All sections of a pressure system with a credible connection to a source of pressure Process vessels which contain liquid levels should have high and/or low trips on the level Compressors Fired vessels Pumps Shell-tube heat exchangers MINIMUM PROVISION OF ESD FUNCTIONS The minimum provision of ESD functions that are provided on a typical offshore oil and gas plant are as follow:All sections of a pressure system with a credible connection to a source of pressure Process vessels which contain liquid levels should have high and/or low trips on the level Compressors Fired vessels Pumps Shell-tube heat exchangers Technical SpecificationsPILZ, PSS3000 for Fail safe applications. Central processing unit with integral test algorithms and redundant design, for use as part of a modular safety-related system with connection to SafetyBUS p?. Processing time Typically 0.5 ms for 1000 instructions The 3-channel diverse structure with integral test and safety algorithms, Suitable for applications conforming to EN 954-1, up to category 4, DIN V 19250, 01/89, AK 6 and EN IEC 61508, SIL 3. Downloading via the RS232/RS485 programming port through a PC Type tested and approved Failsafe modules Standard programmable communication interface Communication module for connecting to Ethernet Modular hardware and software architecture Safety BUS p? communication protocol between Stations I/O self diagnostic Communication / CPU / Channel Redundancy (TMR) Data memory: Standard section: 170 Kbytes Failsafe section: 64 Kbytes 4-digit display for status and diagnostics Programming software PSS WIN-PRO, Windows-based, IL, LD, FBD Supports Application Headers SINEC S5 application protocol, SINEC S7 application protocol, Modbus TCP Supports protocols TCP/IP, H1, RFC 1006 Menu-driven configuration software for the most common PC operating systems Supporting nonvolatile memory in the module s Flash Memory Ethernet connection via Twisted Pair (RJ45) or AUI (IEEE 802.3) Test Connection and status displayed via LEDs Complying Standards IEC-287, IEC-529, IEC-61508, IEC-61511, EN 61000-6-2, 04/99, EN 55011, 08/99, EN 60068-2-6, 04/95 Fail Safe Digital Input Module with following specifications:Failsafe in accordance with EN 954-1, 11/94, up to cat egory 3 if no additional test pulses are used 32 digital inputs Galvanic isolation for a high level of noise suppression Pulse suppression 400 ?s Protection type (EN 60 529, 10/91) IP 20 (installed on module rack) Fail Safe Digital Output Module with following specifications:Fail safe modules type tested and approved by BG and T?V Fail safe in accordance with EN 954-1, 11/94, up to category 3 if no additional test pulses are used 32 digital outputs Galvanic isolation for a high level of noise suppression Switch off Impulse Max. 300 ?s-Switch on Impulse Max. 300 ?s Integral protection circuits Power supply with integral protection and monitoring circuits, for use as part of a modular safety-related system Failsafe modules have type approval Whole system is approved by BG and T?V 24 VDC version for PSS 3000 and PSS 3100 115/230 VAC version for PSS 3000 Integral protection and monitoring circuits Module Sub-Rack Module rack in a redundant design, used to build up the modular PSS 3000 safety system ESD PLC Panel and Marshalling Painting: Electrostatic Powder Coating System type of paint Epoxy / Polyester Color: RAL 7035/32 Thickness of Painting: 70?m (microns) Dimensions: 2100x800x800 mm - Ingress Protection: IP42 for control Cubicles - Type of cubicles: Free standing, hinged doors, Indoor mounting, front & rear access - Air cooled in the control room