Tank Overfill Protection
Transcription
Tank Overfill Protection
Tank Overfill Protection A review of API 2350 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 2 API2350 Edition 4: Scope • Petroleum liquid products • Atmospheric storage tanks – Fixed roof – Floating roof • API2350 is generic and can often be applied on other tank types Spartan Controls Confidential | Page 3 Scope of API 2350 • • • • Storage tanks containing petroleum Larger than 5m3 Non pressurized tanks Products of Class I or II Class Definition Example I Flash Point less than 100°F Motor and Aviation Gasolines II Flash Point equal to or greater than 100°F, Diesel Fuel, Paint Thinner but less than 140°F III Flash Point equal to or greater than 140°F Spartan Controls Confidential | Page 4 Home Heating Oil, Lubricating Oils, Motor Oil API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 5 Why management system? Spartan Controls Confidential | Page 6 Management System Component • Now required by API2350 Edition 4 • A management system is the framework of processes and procedures used to ensure that an organization can fulfill all tasks required to achieve its objectives • Examples: – ISO 9001 Quality Management, – ISO 14001 Environmental Management (Chevron benchmark) – ISO/IEC 27001 Information Security Management, – SA8000 Social Accountability. Spartan Controls Confidential | Page 7 Management System Cont’d • Key Components – – – – – – – Formal written operating procedures (including emergency response) Trained and qualified personnel Equipment systems testing and maintenance Normal and abnormal operating conditions addressed MOC (management of change) Investigation process for near misses and incidents Lessons learned • API 2350 does NOT specify how to develop/deploy a management system Spartan Controls Confidential | Page 8 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 9 What is risk? Risk = Consequence • Probability Spartan Controls Confidential | Page 10 Methods of Risk Assessment • Many methods ranging from qualitative to semi-quantitative to quantitative: – Checklists – Risk matrices – HAZOP approach – Risk Graph – Quantitative Methods – Layers of Protection Analysis (LOPA) Spartan Controls Confidential | Page 11 Example Risk Matrix Who does the risk assessment • Sometimes wide group of company internal competence – – – – – Safety/Quality department Operators department Maintenance engineers Instrument Engineers … • Often 3rd part company – Exida, TÜV, DNV, SISTech, … • Other Consultant Companies Spartan Controls Confidential | Page 12 API 2350 and Risk Assessment • Risk Assessment now required! • Responsibility of the owner and operator • API 2350 does NOT specify how risk assessments should be conducted • IEC 31010 “Risk management – Risk assessment techniques” lists many such methods. Spartan Controls Confidential | Page 13 API 2350 Annex E: • • • • • Consider These Likelihood Factors Frequency, rate and duration of filling Systems used to properly measure and size receipts to tanks Accurate tank calibration (both strapping and verified Critical High) Systems used to monitor receipts Extent of monitoring / supervision of manual and automatic tank gauging • Impact of complexity and operating environment on the ability of Operating Personnel to execute overfill prevention tasks – Filling multiple tanks simultaneously – Switching tanks during receipt – Large elevation changes between tanks and backflow Spartan Controls Confidential | Page 14 API 2350 Annex E: Consider These Consequence Factors • Hazard characteristics of material (product) in tank • Volatility, flammability, dispersion, VCE potential • Number of people onsite who might be affected by a tank overflowing • Number of people offsite who might be affected by a tank overflowing • Possibility of a tank overflowing resulting in (escalation) of hazardous events onsite or offsite • Possibility of impact to nearby sensitive environmental receptors • Physical and chemical properties of product released during overflowing • Maximum potential overfill flow rates and duration • Secondary containment Spartan Controls Confidential | Page 15 Risk Reduction • To reduce risk: – change of operating – by a change of operating procedures and practices – a change of equipment systems and alarms Example: Change Flowrates Example: Increased attendance, man power Example: Install better Tank Gauging, Alarms & AOPS Spartan Controls Confidential | Page 16 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 17 Levels of concerns (LOC) The following levels must be defined in both volume, level & ullage for each tank Level Action Critical High Emergency Response AOPS (if applicable) AOPS Activation. Alarm optional High-high Alarm Terminate/Divert flow. Alert optional Max Working Level Note: • Alarms require actions. • Alerts are optional (e.g. Hi-Alert) Spartan Controls Confidential | Page 18 LOC Determination LOC’s shall take the floating roof into account Spartan Controls Confidential | Page 19 Annex D provides some guidance for determining LOC’s Spartan Controls Confidential | Page 20 Determining Response Time • • • • • Flow rate Verification of the Alarm Communication Time Action time Completion time Spartan Controls Confidential | Page 21 LOC Considerations • LOC shall be up-to-date and a periodic review required no more than 5 yrs apart • Changes require a review of the LOC – Physical Changes to the tank – Recalibration or re-strapping of the tank – Change of tank gauging equipment – Change of valves – Operational Changes e.g. product & response time – Modified flow-rate / pump-velocity Spartan Controls Confidential | Page 22 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 23 Overfill prevention systems • What are the requirements for an overfill prevention system? • It depends on the risk • It depends how the tank is operated Spartan Controls Confidential | Page 24 Tank Categories • Operators/Owners shall categorize each tank • A way to classify tank overfill systems • The API 2350 defines – Cat. 1 – Cat. 2 2 – Cat. 3 1 Spartan Controls Confidential | Page 25 3 Tank Categories Attendance Category #3 Monitored from local or remote control center Personnel at the premises Monitored from local or for local monitoring of remote control center receipt Complex facility, multiple tanks are being filled Transfers simultaneously, or operator may be distracted Spartan Controls Confidential | Page 26 Category 3 – Configuration Tank level and alarm are transmitted to remote location (control room). Alarm is independent of ATG system and set at High-High LOC. Requires Local “manual” shutdown or diversion For unattended operation, alarm shall automatically notify transporter or automatically terminate receipt (AOPS) and receipt termination shall commence in event of power outage Spartan Controls Confidential | Page 27 27 Other Tank Categories Attendance Category #3 Monitored from local or remote control center Category #2 Semi-attended facility Personnel at the premises for local monitoring of receipt Monitored from local or remote control center - Continuously during the first and last 30 minutes of receipt Transfers Complex facility, multiple tanks are being filled simultaneously, or operator may be distracted Same as category 3 Spartan Controls Confidential | Page 28 Category 2 – Configuration Tank level (ATG required) and alarm is transmitted to remote location (control room) ATG Alarm set at LOC: HH Alarm are not independent of ATG system (same sensor for ATG and alarm) May use Cat 2 at fully or semi attended facility if receipts monitored at the control room On site monitoring required 30 minutes at start, at end of receipt; for semi attended transporter must participate in monitoring Alerts recommended at LOC: H Spartan Controls Confidential | Page 29 29 Other Tank Categories Category #3 Category #2 Category #1 Monitored from local or remote control center Semiattended facility Fully-attended facility (locally monitored) Personnel at the premises for local monitoring of receipt Monitored from local or remote control center - Continuously during the first and last 30 minutes of receipt - Continuously during first and last hour of receipt - Once every hour during receipt Transfers Complex facility, multiple tanks are being filled simultaneously, or operator may be distracted Same as category 3 Full focus on one receipt at a time, and not distracted with other duties or responsibilities Attendance Spartan Controls Confidential | Page 30 Category I – Configuration Does not have transmitted alarms Tank Level is determined by HAND gauging or local Automatic Tank Gauging (ATG) system. Requires Local “manual” shutdown or diversion or transporter shutdown after receiving “manual” communications from facility Use only at fully-attended facilities Monitor continuously first and last and every in-between hour of receipt Do not use for high frequency or complex receipt operations Spartan Controls Confidential | Page 31 31 If response-time is not calculated... Description Min HiHi-Level Response Time @ max fill rate* 1 Manual reading 45 minutes 2 Automatic Tank Gauging (ATG) 30 minutes 3 ATG + Independent Overfill 15 minutes Category *) Guideline by API for manually operated overprevention systems (unless a detailed response time has been calculated for the specific tank). 3 in. at a minimum. Consequently According to API 2350: Installing a Tank Gauging System and overfill alarm can increase the tank’s storage capacity Spartan Controls Confidential | Page 32 Critical High HiHi Modern tank farm operations call for a Category 3 configuration Cat3 Cat2 Cat1 Spartan Controls Confidential | Page 33 We always advocate the usage of category 3 systems since: • Required for most tanks • Given all things equal – Higher category equipment safer than lower • Cat 3 suggested even if not required today – Makes the installation future-proof – Allows for operations efficiency improvements ($$$) – Maximizes tank utilization ($$$) Spartan Controls Confidential | Page 34 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Overfill Prevention Procedures • AOPS • Proof testing • Wireless Spartan Controls Confidential | Page 35 What is an AOPS? • Automatic Overfill Prevention System Sensor • Closed Loop Control Spartan Controls Confidential | Page 36 Logic Solver Actuator Requirements for AOPS AOPS are optional Facility Existing facilities New facilities Requirements Comply with Annex A Comply with IEC61511 /S84 aka ”SIL” Remember: These requirements are likely to change in the future i.e. becoming more stringent Spartan Controls Confidential | Page 37 Annex A: AOPS • • • • • • Design to fail safe No wireless Be able to operate manually Logic solver shall be equipped with watchdog Procedures to handle any failures Proper documentation Spartan Controls Confidential | Page 38 New tanks: AOPS 2x5900 Independent High-High Level Alarm Automatic Tank Gauge Rosemount 5900 Radar Level Gauge Rosemount 5900 Radar Level Gauge High-High Alarm AOPS Rosemount FCU Data Concentrator Rosemount 2410 Tank Hub Rosemount 2410 SIL2/SIL3 Discrete Signal Tank Hub Connection to TankMaster (optional) Rosemount FCU Data Concentrator Spartan Controls Confidential | Page 39 Includes Visual & Audible Alerts (optional) TankMaster Tank Gauging System Rosemount 5900 2in1 Radar Level Gauge Automatic Tank Gauge Level Independent High-High Level Alarm Overfill New tanks: AOPS 2in1 High-High Alarm AOPS SIL2 Discrete Output Rosemount FCU Data Concentrator Rosemount 2410 Tank Hub Rosemount 2410 Tank Hub Connection to TankMaster (optional) Rosemount FCU Data Concentrator Spartan Controls Confidential | Page 40 Includes Visual & Audible Alerts (optional) TankMaster Tank Gauging System New tanks: AOPS 5900+2120 Independent High-High Level Alarm Automatic Tank Gauge Rosemount 5900 Radar Level Gauge Rosemount 2130 Vibrating Fork SIL 2 Discrete Output Rosemount FCU Data Concentrator Rosemount 2410 Tank Hub High-High Alarm Automatic Overfill Prevention System (AOPS) Connection to TankMaster (optional) Includes Visual & Audible Alerts (optional) Spartan Controls Confidential | Page 41 TankMaster Tank Gauging System API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Overfill Prevention Procedures • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 42 Proof testing • OPS shall be tested upon initial installation • OPS shall be re-tested during operation • Schedules and testing procedures shall be documented for periodic testing, inspection, and maintenance – Level Gauge, Logic Solver, Final Element, Alarm (if applicable) • Device Manufacturer’s proof-test procedures shall be adhered – Wet test not required – Test can be partial – Do not fill tank above max working level Spartan Controls Confidential | Page 43 Hand Gauges • Testing of hand gauges shall comply with requirements in API MPMS Ch. 3.1A – Comparison with a reference at least annually Spartan Controls Confidential | Page 44 Level Gauges • Testing of continuous-level sensors shall comply with requirements in API MPMS Ch. 3.1B – Gauge verification quarterly – Can be pushed out to annually if stable operating experience • Point- level sensor shall be tested 2 / years – Unless supported by technical justification (i.e. a probability of failure on demand calculation); • All other OPS components required to terminate the receipt (e.g. alarm) shall be tested at least annualy Spartan Controls Confidential | Page 45 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Overfill Prevention Procedures • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 46 The Wireless Options • API 2350 gives no guidance; the technology was considered to premature. However the interpretation from experts is that: • Wireless is OK except for AOPS Spartan Controls Confidential | Page 47 Wireless OK for category 1, 2 and 3 (but not AOPS) TankMaster 5300 Spartan Controls Confidential | Page 48 AOPS with Advisory Wireless TG Sensor TG-System Controller/ Logic Solver Optional SIL2/3 TÜV/DIBt WHG Approved Relay Output (optional) Actuator Spartan Controls Confidential | Page 49 API2350 Edition 4 • Scope • Management System Requirements • Risk Assessment • Level Of Concerns • Overfill Prevention System • Proof testing • AOPS • Wireless Spartan Controls Confidential | Page 50 More Reading • Module I: API2350 Overview – Authored by Phil Myers, API2350 Committee chairman • Module II: Example Solutions – Emerson-solutions for category 1-4 Go to www.rosemount-tg.com Spartan Controls Confidential | Page 51