FS-8550-4100-0001

SPECIFICATION FUNCTIONAL SPECIFICATION Client CNOCC Always refer to this number Plant Nanhai SMPO & EB Plant 0331 04011 Location Nanhai Refinery, China. Dept./Sect. Project Specification Doc. No. FS-8550-4100-0001 Rev. A A 2001-10-26 FOR BDEP DSI CTD JK REV. DATE DESCRIPTION PREPARED CHECKED APPROVED FUNCTIONAL SPECIFICATION FOR FIRE AND gAS DETECTION SYSTEM INDEX TOC \o "1-4" \w 1. Project Safety Philosophy 2 1.1 INTRODUCTION 4 1.2 REFERENCES 5 1.3 ABBREVIATIONS 6 1.4 PROTECTION 7 1.4.1 General 7 1.4.2 Flammable Gas 7 1.4.3 Fire 8 2. EMERGENCY POWER 8 3. FIRE AND GAS DETECTION SYSTEMS 9 3.1 General 9 3.2 Essential Features 9 4. Heat Detection 11 4.1 Heat Detection By Polyflow Tubes 11 5. Gas Detection 12 5.1 General 12 5.2 Gas Detection Alternatives 12 5.3 Toxic Gas 12 5.3.1 General 12 5.3.2 Toxic Gas Detection 13 5.3.3 Toxic Gas Safeguarding 14 5.4 Flammable Gas Detection 15 5.4.1 General 15 5.4.2 Flammable Gas Detection 15 5.4.3 Flammable Gas Safeguarding 16 5.5 Smoke Detection 17 INDEX (cont.d) 5.6 OTHER SAFETY SYSTEMS 18 5.6.1 General 18 5.6.2 Manual Alarm Call Points (MCP) 18 5.6.3 Oil Mist Detection 18 5.6.4 Fire Alarm Mimic Panels 19 5.6.5 Distributed Control System (DCS) 20 5.6.6 Alarms 21 5.7 Fire protection 22 5.7.1 Fire and Smoke Detection System (Indoors, excluding Analyzer Houses) 22 5.7.2 Fire Protection System 23 5.8 FIRE PROTECTION SYSTEMS 24 5.9 Analyser House 001 and 002 Protection 25 5.10 Pre-Discharge Alarms 26 5.11 Maintenance override 27 5.12 sTART-UP BYPASS 27 5.13 RESET REQUIREMENT 27 1.​ Project Safety Philosophy 1.1​ INTRODUCTION Note: This specification is issued with “HOLDS” on tag numbers for certain pushbuttons and lamps which will be determined in detailed engineering. The primary objective of this philosophy is to ensure that the Fire and Gas safeguarding design of the Nanhai facilities reduces the risk to plant, personnel, third parties, the environment, production revenue and capital investment during operation of the facilities, to As Low As Reasonably Practicable (ALARP). This shall be achieved by applying the appropriate Codes and Standards as detailed in this specification, and by the application of quality assurance procedures coupled with Safety studies, undertaken during the design process. The facility will be designed to fulfil the following HSE requirements: a)​ Foremost account will be taken of the health and safety of employees, and all other persons who may be affected directly or indirectly by production activities. b)​ Proper regard will be given to the conservation of the natural environment and local amenities. c)​ The protection of assets will be ensured. d)​ The design shall recognise the possibility of all hazards involved in the facility/operation and eliminate/mitigate the resultant risk by identifying and analysing the risk factors and providing means to eliminate/mitigate these risks. e)​ Construction of all facilities will employ materials, which are suitable for the service and environmental conditions. f)​ The potential release of hydrocarbons will be minimised by appropriate provisions of isolation, process and emergency shutdown and depressurising systems in accordance with the appropriate engineering guides, Codes and Standards. g)​ Eliminating or minimising the spread of spills and leaks will be considered by provision of the appropriate degree of containment and drainage. h)​ The facilities design will cater for protecting operating and maintenance personnel during normal operations and against contingency situations involved in start-up, shut-down and emergency control of the facilities. i)​ Adequate ventilation will be provided throughout all areas and spaces to preclude the accumulation of combustible or toxic vapours. j)​ The layout of equipment and process systems will ensure maximum possible separation between potential sources of leakage and potential sources of ignition with sufficient means of escape. The possibility of the event escalating will also be considered in the orientation and placing of equipment on the platform. 1.2​ REFERENCES All documents, regulations, Codes and Standards referred to shall be the latest editions current at the time of preparation of a project specific specification. In addition to the above, specific Codes and Standards applicable to individual items of equipment/materials shall be identified in the specifications for that item of equipment/materials. Relevant sections from the following documents have been used and are referenced in this specification: The design and engineering of fire-fighting and gas detection systems shall be in accordance with the following codes, authority require​ments and drawings: SHELL DEP’S: ​ 32.30.20.11-CSPC, Fire, Gas and Smoke Detection Systems, July 2001. ​ 32.80.10.10-CSPC, Classification and Implementation of IPF, June 2001. ​ 80.47.10.30-CSPC, Assessment of Fire Safety of Onshore Installations, August 2001. ​ 80.47.10.31-CSPC, Active Fire Protection Systems and Equipment for Onshore Facilities, August 2001. ​ MF 87-0179 Hydrogen Sulphide (Shell HSE committee publication) MF Report EUROPEAN STANDARDS: Construction and performance of fire, gas and smoke detectors shall meet the standards of the country where they will be used. In the absence of national standards, the following European standards shall be followed, unless otherwise permitted by the Principal. ​ Heat detectors EN 54 ​ Flame and ionisation-type detectors EN 54 ​ Combustible (flammable) gas detectors EN 50054, EN 50055, EN 50056, EN 50057, EN 50058 ABB PROJECT DRAWINGS: 60-8550-8500-0001 Rev B Instrument Index Unit 8500 & 4100 61-8140-4100-0001 Rev.B F&G Detection Layouts Unit 4100 & Unit 4200 61-8140-4300-0001 Rev.B F&G Detection Layouts Unit 4300 61-8140-4400-0001 Rev.B F&G Detection Layouts Unit 4400 & Unit 4500 61-8140-4600-0001 Rev.B F&G Detection Layouts Unit 4600 61-8140-4700-0001 Rev.B F&G Detection Layouts Unit 4700 & Unit 4800 61-8140-4900-0001 Rev.B F&G Detection Layouts Unit 4900 61-8140-5300-0001 Rev.B F&G Detection Layouts Unit 5300 61-8140-8380-0001 Rev.B F&G Detection Layouts Unit 8380 25-8110-8500-F&G-001 HOLD - Gas detection Control System 25-8110-8500-F&G-002 HOLD - Analyser House No.1 Protection System 25-8110-8500-F&G-003 HOLD - Analyser House No.2 Protection System 64-8550-4100-0001 Auxiliary Room Layout FAR - 1 64-8550-4100-0002 Auxiliary Room Layout FAR – 2 64-8550-4100-0007 Control Room 1.3​ ABBREVIATIONS CCR (CCB) Central Control Room (Building) CCTV Closed Circuit Television Camera DCS Distributed Control System DEP Design and Engineering Practice EB Ethyl Benzene EBHP Ethyl Benzene Hydro Peroxide EO Ethylene Oxide FAMP Fire Alarm Message Panel FAR Field Auxiliary Room FGC Fire and Gas Console FGS Fire and Gas System GC Gas Chromatogragh GRP Glassfiber Reinforced Polyester HVAC Heating / Ventilation / Air Conditioning HBPG High Back Pressure Generator HSE Health, Safety and Environment IPF Instrumented Protective Function IPS Instrumented Protective System LED Light Emitting Diode LFL Lower Flammable Limit LFP Local Fire Panel MCP Manual Call Point MOS Maintenance Override Switch MPC Methyl Phenyl Carbinol MPK Methyl Phenyl Ketone OBL Outside Battery Limit PO Propylene Oxide SMPO Styrene Monomer & Propylene Oxide plant STEL Short Term Exposure Limits TLV Threshold Limit Value TOS Test Override Switch VESDA Very Early Smoke Detection Apparatus 1.4​ PROTECTION 1.4.1​ General The degree of protection required depends on a number of factors, which represent the degree of hazard present, danger to personnel, risk to the installation and environment. When the risks have been established it is the objective of the safety philosophy to identify the acceptable level of risk and to specify those measures that will be adopted to ensure that the risks are reduced. Factors, which are considered to be important in determining the risk, include: ​ Personnel Safety - Level of manning ​ Types of communication ​ Means of escape ​ Investment - Magnitude ​ Consequential loss - Loss of production ​ Loss of reserves ​ Probability of fire - Type of equipment ​ Standard of maintenance ​ Location ​ Containment of fire - Location ​ Hydrocarbon inventory The installation will be broken down into areas of risk. Considering the above factors, they are: a) High risk Increased probability of hazard which would be difficult to contain and would result in danger to personnel and consequently an investment loss. b) Medium risk Areas which do not directly fall into categories a) or c) c) Low risk Limited probability of hazard occurrence, low loss of investment Areas of high risk include: fuel and chemical storage areas, fired equipment, gas turbines, internal combustion engines and compressors. Areas of medium risk include all areas of control and telecommunication rooms. Areas of low risk include normally unmanned areas and areas with non-hazardous equipment. 1.4.2​ Flammable Gas Gas release can occur in or around an installation as a result of: *​ Abnormal operating circumstances *​ Failures of flanges, fittings, pipelines or equipment. The ignition of the flammable gas-air mixture can produce fire and/or explosions capable of causing injury to personnel as well as major structural failure and damage to plant. The aim is to minimise the risk of flammable gas accumulations and potential ignition sources and, therefore, to shut in gas sources on the detection of unacceptable levels and provide facilities to depressurise them. 1.4.3​ Fire In accordance with normal practices the project philosophy will be to consider one major incident at a time. Fire can occur at any location from a variety of fuel sources. The protection philosophy will be rapid detection, elimination of the fuel sources and automatic or manual extinguishing of the fire depending on its location and severity. In evaluating potential risk to personnel and property, the characteristics of the materials being handled, pressures and temperatures, as well as the types of equipment being used will be studied. 2.​ EMERGENCY POWER On loss of both main and emergency power, the emergency battery power supply systems will be sized adequate to provide continuous power to the following systems: System Duration Fire and Gas Detection and Alarm system 180 min Emergency shutdown system 180 min Process Monitoring and Control System 45 min Telecommunication system [note1] 180 min Note 1: including PA (telephone PABX), Radio link, Portophone docking station, satellite. 3.​ FIRE AND GAS DETECTION SYSTEMS 3.1​ General The overall objective of the fire and gas system is, as far as reasonably practicable, to monitor all air spaces where a fire or accumulation of a potentially flammable mixture may occur and to detect these events, alert personal, initiate timely executive actions in order to minimise the consequences of the event. The basic requirements of the fire and gas detection systems are as follows: 1. Rapid detection of the undesired event; flammable gas / liquid release and fire. 2. On confirmed detection, simultaneously: *​ Raise Alarm *​ Isolate the source of release *​ Isolate potential sources of ignition *​ Exclude air where fire is confirmed (close HVAC dampers etc) *​ Apply extinguishant where fire is confirmed *​ Protect adjacent equipment to prevent escalation of the incident 3.2​ Essential Features The instrumentation for fire and gas detection shall be available at all times even during a total plant shutdown. The fire and gas detection system shall therefore be separate from the DCS system. For the implementation of the fire and Gas Logic the same equipment type as the IPS shall be used. The fire and Gas IPS shall be segregated from the process IPS to the extent that the maintenance can be carried out on the process IPS without affecting the Fire and Gas IPS. (I.e. during shut down the F&G IPS is still expected to be operational). The presentation of controls and alarms associated with this system shall be made visible via a FAMP message. The fire and gas system will be based on the provision of suitable field detector devices, which alarm to the fire and gas control panel. Upon detection of an alarm condition, suitable audible and visual alarms will be initiated at the Fire and Gas panel. These alarms will identify the type and location of the detection device activated at the main fire and gas panel and at any other defined control point or repeater station. The system will be self-monitoring to detect faults that may affect the operation of the system. Detection of a fault will register an appropriate signal at the alarm panel and any annunciation panels or system displays. The detection loops shall not be fail safe. Signals from the fire and gas detection system may be used to initiate operation of fire fighting equipment or systems. Plant shutdown and depressurisation may be initiated via the ESD system. The fire and gas system will be supplied with power from the uninterruptible power supply (UPS) and will include battery back up with a dedicated battery charger. The instrumentation for fire and gas detection shall be available at all times even during a total plant shutdown. The fire and gas detection system shall therefore be separate from the DCS system. The presentation of controls and alarms associated with this system shall be made visible via a FAMP message. All components shall be accessible for maintenance and testing without disruption to routine operation of the plant, interruption of overall protection monitoring or undue degradation of the system (including sensors, through logic and annunciation to activation). The fire and gas detection system will be physically arranged so that a single failure in it is unlikely to cause critical impairment of the system’s safety function. This will be assessed within the system reliability/availability modelling and the Emergency System Survivability Analysis. Detection modes that are arranged to cause plant shutdown will be generally on a two out of N voting arrangement to reduce the possibility of spurious shutdowns, where N is a minimum of three detectors in the same fire zone. A revealed fault condition shall be arranged to vote as an alarm condition. However, any one pneumatic detection system will each operate as a single loop. Field detector types shall be selected on the basis of: a) ​ Which type gives the earliest detection of the event b) ​ Freedom from spurious operation c) ​ Suitability for the ambient environmental conditions d) ​ An optimum design and limitation of the number of detectors e) ​ Proven operation in similar situations f) ​ Inherent reliability g) ​ Low maintenance requirements Transmitter types of sensors do not usually require a control module. Control Modules should be suitable for single man calibration. The control module shall contain as a minimum the following self-diagnostic features: ​ Open loop detection (input and output) ​ Short circuit (input and output) ​ Earth fault(s) ​ Power supply failure, e.g. low battery voltage (of UPS) ​ Control Unit failure ​ System fault ​ End of sensor life (if applicable) Alarm level(s) settings shall be protected against changes by unauthorised persons, e.g. by means of a key-lock. 4.​ Heat Detection 4.1​ Heat Detection By Polyflow Tubes The automatic water spray systems are connected to pressure transmitters activated by fire detection via dual plastic tubes pressurized with instrument air. The plastic tubes, located above the protected equipment, melt in case of fire. Loss of instrument air pressure in one loop will result in an alarm in the DCS. Upon loss of pressure in two loops the water spray system is activated automatically. The hot oil pumps P-5301 A/B and P-5302 A/B, P-4615 A/B/C, unit 4800 and unit 4900 will be protected with heat detection without a spray system. This is a single tubing fire detection system. The FireWater Spray System will activate the following: ​ General Fire Siren will be triggered. ​ The corresponding deluge valve will be opened. ​ The FireWater Pump will be started. ​ Message on the FAMPS will be displayed. ​ The Common Fire Lamp (850XA –hold) and Audible Alarm (850UA-hold) on FGC will be activated. 5.​ Gas Detection 5.1​ General The type of gas detection is characterized by: ​ The area of detection. The alternatives are line of sight (only valid for flammable gas) or single source detection. ​ The type of gas to be detected. Toxic gas and/or flammable gas. When a gas leak (toxic or flammable) in Nanhai is detected, the common gas lamp is flashing on the FGC (850XA-024). 5.2​ Gas Detection Alternatives In single source detection possible leak sources are monitored by strategic location of separate detectors (e.g. at flanges and pump seals). In a plant, area monitoring is easier to realize due to the high number of possible leakage points and toxic and flammable gases, which can be found throughout the whole plant. A good example of area monitoring is the detection of flammable hydrocarbons with a density heavier than air (e.g. LPG handling equipment) by means of a "line of sight" based upon the infrared absorption principle. In this way whole areas can be monitored with a few detectors. The location of “line of sight” detectors will be along pump rows near the pipe racks and along roads. Path detection from different heights may be necessary. The densities of the gases to be detected have to be taken into account. For gases heavier than air, detection shall be done at an elevation of 0.1 to 0.2 meter above grade to avoid fouling and disturbances. For gases, which are lighter than air, detection must be done above the leak source. Strict requirements are valid for fastening and supporting. The maximum length to be covered by the detectors is about 50 meter. With longer distances the detector operability would decrease due to partial obstructions and bad weather conditions. 5.3​ Toxic Gas 5.3.1​ General Toxic gas detection is based upon concentration changes measured by a gas chromatograph (GC). Strategic located sampling points are connected to the gas chromatograph, which will analyze the individual sample streams sequentially. For the location of toxic gas sampling points all the relevant factors, such as equipment type, sources of leakage, unit layout and prevailing wind direction have been taken into account. Small quantities of toxic gas have to be detected more accurately than small quantities of flammable gas. This is because critical gas concentrations regarding toxicity are lower than critical gas concentrations of flammable gases. H2S detectors shall be located close to potential sources of leakage, such as at pump and compressor seals, and also at 2 to 4 meters distance to detect further dispersion of gas. The type of H2S detectors to be used is the electrochemical cell-type due to their superior response time compared to other types (such as semi-conductor). For H2S gas detectors the alarm level setting shall be minimum 10ml/m3 H2S. The largest amount of potential PO sources are in the 4400 an 4500 unit. PO detectors will be located at positions around the 4400 and 4500 unit close to adjacent pipe racks as much as possible to avoid that the detectors are obstacles in the process area. Equipment handling PO outside the units 4400 and 4500 shall be provided with a PO gas detector close to the equipment. The polyols unit (unit 2400) is a potential source of PO/EO gas. The PO/EO sampling points are located directly at/around the critical equipment (reactor circulation pump, drain vessel pit and other vessels). The individual toxic gases can be detected by the gas chromatograph located in analyzer house AH-1. Benzene/ethylbenzene in the EB unit (unit 4900) will be detected by a gas chromatograph in analyzer house AH-2. Multiple sampling points will be installed at critical locations within the unit. Apart from alarm signals in the F & G system, the gas c