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Instrumentation Design & Detailed Engineering
- 1. OGC EPC LEAD TRAINING I&C TRAINING FOR NON-I&C PROFESSIONALS
- 2. ► The purpose of this session is to inform non-I&C professionals of the inner workings of the I&C discipline. • Workflow • Deliverables • Interdiscipline interfaces ► The focus is on detailed design phase for an EPC project ► If we each understand what other disciplines do and why we can work together more effectively ► There’s less voodoo involved than you may think 2 INTRODUCTION
- 3. 3 SAFETY TOPIC Tank Overfill Buncefield fuel depot, U.K.
- 5. 5 SAFETY TOPIC Tank Overfill Buncefield fuel depot, U.K. December 11, 2005
- 6. 6 SAFETY TOPIC Tank Overfill – Layers of Protection
- 7. 7 SAFETY TOPIC Tank Overfill – Layers of Protection
- 8. ► What is I&C? ► What doesn’t I&C do and why not? ► Who do we interface with? ► Main activities and deliverables ► Where do we usually have problems? 8 AGENDA
- 10. ► Instrumentation • Sensors to measure process variables ► Flow ► Level ► Pressure ► Temperature ► Etc. • Final elements to make adjustments to the process ► Control valves ► On / off valves ► Motor controls ► Etc. 1 0 What is I&C?
- 11. ► Controls • The system that takes the measurements from the sensors, compares against setpoints, and tells the final elements (valves) what to do • Hardware and software ► Distributed Control System (DCS) ► Programmable Logic Controller (PLC) ► Safety Instrumented System (SIS) ► Vibration Monitoring ► Etc. 1 1 What is I&C?
- 12. What doesn’t I&C do and why not? 1 2
- 13. 1 3 What doesn’t I&C do and why not? ► System integration • Physical building and assembly of panels • We often do conceptual design • Full details may be our design or by a third party • Sub to third party for fabrication, interconnect, testing ► Programming • Coding of the control system • Graphics • We define what needs to be done • Sub to third party specialist to program • Some details left to their expertise
- 14. Who do we interface with? 1 4
- 15. 1 5 Who do we interface with? ► Process • Provides the main inputs (P&IDs and process data) for I&C work ► Mechanical • I&C provides input into packaged equipment specs • Mechanical outputs I&C dimensions and details from equipment vendors ► Piping • Need a lot of information from each other • Layout and locations of instruments and valves, straight run and nozzle requirements, dimensions, locations of air users ► Electrical • Need a lot of information from each other • Power and grounding, motor controls, cable quantities and routing, communications ► C/S/A • Buildings such as analyzer shelters or RIE Building
- 17. ► Specify I&C requirements for mechanical equipment ► Specify and procure I&C materials ► Instrument index ► I/O list ► Installation details ► Instrument location plans 1 7 Main activities and deliverables LEGEND Prefer to maximize SPI use Little or no SPI
- 18. ► Instrument cable schedule ► Instrument wiring diagrams ► Control narratives / cause & effect diagrams ► Perform Factory Acceptance Tests (FAT) ► Loop drawings 1 8 Main activities and deliverables LEGEND Prefer to maximize SPI use Little or no SPI
- 19. ► Manufacturer standard or customize to client specs? • Usually customized • Major cost, schedule, operability / maintainability impact • Requirements for control system, instruments, nozzles, accessibility, documentation • Perform document reviews, assist with FAT ► Compressors ► Fired equipment ► Other packaged equipment ► Limited scope on vessels, heat exchangers, pumps, fans, etc. 1 9 I&C requirements for mechanical equipment
- 20. ► Large and long-lead items first • Delivery may be a concern • May drive plant layout • Usually multi-discipline impacts ► Control systems ► Instrument buildings ► Complex analyzers ► Meter skids ► Some valves and specialty instruments ► Usually written spec (not data sheet) 2 0 Specify and procure I&C materials
- 21. 2 1 Specify and procure I&C materials
- 22. 2 2 Specify and procure I&C materials
- 23. ► Inlines and vessel trim next • Need process data to do specs • Piping needs dimensions, straight run requirements, etc. • Relief valves occur late ► Valves ► Flow meters ► Level instruments 2 3 Specify and procure I&C materials
- 24. ► Basic transmitters and gauges last • Need process data to do specs • Usually largest quantities • Delivery generally fast • Many available within days if necessary • Impact on other disciplines is very small ► Flexible scheduling needed 2 4 Specify and procure I&C materials
- 25. ► Purpose is to link all other documents together ► For every instrument tag it provides: • Instrument type • Description • P&ID number • Loop number • I/O type 2 5 Instrument index
- 26. ► Defines scope for who furnishes and who installs ► Defines physical location • Location plan • Equipment number • Line number ► Defines how to install references • Installation details, wiring drawings, loops ► Defines PTA or TA, work areas and turnover system ► Subs and EIC superintendents use for progress tracking 2 6 Instrument index
- 28. ► Instrument index focuses on physical devices and installation ► I/O list focuses on details of software and control system programming • Defines where each instrument wires to control system (the I/O point) • Defines how each point is to be programmed • Alarm setpoints and priorities may be included, or may be a separate document ► Quantities are used to define the size of each control system ► Main document used by the programmer (third party) to do their work 2 8 I/O list
- 29. ► Defines the materials and methods for installing each instrument • Supports (pipe stands) • Process connections • Conduit connections • Heat trace and insulation ► Selected based on process needs, accessibility, electrical considerations ► Subs are the main user ► Also used by electrical (with instrument index) to define heat trace requirements 2 9 Installation details
- 31. ► Shows locations of instruments, junction boxes, and control systems requiring wire ► Instruments without wire aren’t shown ► Sometimes we show instruments that require tubing but no wire (not always) ► Requires piping design to be substantially complete (90% Model Review) • Must know locations of connections to piping and equipment • XYZ coordinates are extracted from the 3D model ► Allow visualization of wiring and conduit routing • Used by subs to estimate materials and plan work ► Used by electrical for grounding, cable tray, and heat trace design 3 1 Instrument location plans
- 32. 3 2 Instrument location plans
- 33. ► Defines each cable type, how to route, where terminated ► Developed in parallel with location plans and wiring diagrams ► I&C provides basic details on each instrument cable • Electrical provides additional details • Electrical incorporates into master cable schedule • Close coordination required on power cables for instruments 3 3 Instrument cable schedule
- 34. ► Indicates every wire entering and leaving every panel ► Includes signal cables, communication cables, fiber optics ► Cables are pulled to panels based on cable schedule ► Once all cables are pulled to a panel, termination work begins ► Instructs electricians where to terminate wires inside junction boxes, panels, and at control system ► For motors, closely coordinated with electrical: • Motor schematics may sometimes be late deliverable for electrical but I&C at least needs typical schematics to be able to design • Interposing relay panel design 3 4 Instrument wiring diagrams
- 35. 3 5 Instrument wiring diagrams
- 36. ► Process defines purpose and intent of each loop • Controllers • Interlocks • Permissives • Modes of operation or sequence of operation ► I&C provides additional details and adds functions as information becomes available ► After the programmer finishes basic I/O configuration and graphics, they use these documents next • Program complex controllers • Program interlock and permissive logic • Program logic sequences 3 6 Control narrative / cause & effect diagrams
- 37. 3 7 Control narrative / cause & effect diagrams
- 38. ► A witnessed approval and testing process ► Verify what was built or programmed meets spec, matches drawings, functions as intended ► Fix problems in shop before shipping ► Performed on: • Mechanical equipment that comes with a control system or significant instrument scope • Instrument buildings • Meter skids • Complex analyzers • Control system hardware • Control system graphics and programming 3 8 Factory Acceptance Tests (FAT)
- 39. ► Not a construction document ► Nearly all information on loops is already provided in other documents ► Loops link the wiring diagrams and location plans together in one place ► Used for loop checkout and turnover ► Extremely useful for troubleshooting 3 9 Loop drawings
- 41. Where do we usually have problems? 4 1
- 42. ► Usually due to late client changes or receipt of more detailed equipment information ► Requires re-evaluation of instruments and valves ► May change dimensions and cascade into piping changes 4 2 Process data changes Multi-discipline specs / drawing reviews ► Everyone gets busy ► Inadequate input into specs for complex items ► Inadequate review of vendor drawings by other disciplines ► Not attending FAT ► Problems that could have been prevented make it to the field
- 43. ► Usually because of vendor “black boxes” on P&IDs ► Shows up most visibly with changes in cable schedule ► Each item impacts many documents and takes time to capture 4 3 “Hidden” instruments and control panels Instruments lost or damaged ► Water damage (outside storage) – usually come with equipment ► “Borrowed” for another project or maintenance ► Used by workers as a ladder to get to out-of-reach items ► Don’t know there’s a problem until hydrotest or loop check ► CRISIS!
- 44. ► Usually panels with Z-purge or vortex cooler, analyzers ► Not shown on P&ID unless I&C adds it, piping is unaware of locations or quantities until informed ► Some normal items like a control valve in a remote location 4 4 Air users that don’t get air Planning for construction support / initial ops ► Early planning is critical ► Tool kit (literally) and skill set for I&C engineers and designers vs. instrument technicians and turnover staff are very different ► Each have a part to play, generally not interchangeable ► Plan early so the right tools and skills will be available
- 45. ► I&C relies on information from process and mechanical ► I&C is usually last off the project ► A slip in early dates cascades to a crunch on I&C ► Leads to… 4 5 No relief on schedule due to changes Issuing incomplete information ► Issue on time but with holds for information? • May help construction make progress • More engineering and design labor required to retouch drawings ► Wait for more complete information? • Drawings can be issued “whole” • Causes schedule delay, and it would be nice to have…
- 46. ► Remember earlier about simple transmitters and gauges? • Short delivery – not schedule critical • No other disciplines affected by them • Among the last items to be installed ► So why do we rush to get them bought and to the field? ► Causes problems • Sit in warehouse for 6-12 months waiting to be needed • Forces limited resources to work on items that are lower priority • Could be working on items that actually affect other disciplines ► Consider these fill-in work to help level our staffing 4 6 Get it bought!
- 47. 4 7 Questions and Discussion
Editor's Notes
- Opening discussion: Discussion on Questions: Can ask questions during presentations. We will pass the mic. We are on a aggressive schedule to complete in our allotted time so if you can stay after I will be glad to answer anything you want.
- You will be amazed about how much I&C really does .
- Since 1962 there have been over 20 major tank farm fires, almost all due to tank overfill. Standards have attempted to address by recommending independent high level alarms and/or shutoffs. Many older tanks still lack these features and only have a level gauge, maybe a transmitter, but they rely on the same sensor so if one fails, both often fail. The technology frequently used is known to be unreliable. There are better technologies but they are much more expensive. This is Buncefield on a normal day before they had a major fire that happened when they overfilled a tank that was receiving gasoline from a pipeline
- Tank that overfilled had a local level gauge with transmitter and independent high level shutoff switch. It was unnoticed (or accepted as routine) that the local level gauge was no longer recording changes in level. The transmitter also wasn’t working since it used the same sensor as the local gauge. Unknown to the operators the independent high level switch also was failed because it was not being correctly used (not due to instrument failure). The tank continued to be filled past its high level point and overflowed onto the ground for more than 20 minutes. As liquid overflowed, it splashed against a tank girder which caused it to spray out and vaporize into a cloud. Offsite CCTV captured the vapor cloud spreading out into the public. The cloud was noticed by tanker truck drivers and the public before operators did.
- Vapor cloud found an ignition source, believed to be from the fire-water pump being turned on, and caused an explosion. Final tally: No fatalities, but 43 people injured, mostly members of the public. Over 2000 people evacuated. 20 large storage tanks caught fire due to overfill, subsequent vapor cloud explosion from gasoline vapors, fire Significant offsite damage UK’s largest fire since WW II, burned for 5 days
- Demonstrates importance of layers of protection. Any one of the instruments working right could possibly have prevented the incident. The only way this occurs is if all layers fail. Sometimes operations forgets that there are multiple layers for a reason, and begins to use last-line-of-defense safety features as the normal operating method. For example, when tanks have an automatic high level shutoff, sometimes operators no longer closely monitor tank levels and stop flow manually like they’re supposed to. They rely on the automatic shutoff only and if it fails, there’s no protection. This can happen due to operators being operators, or in this case, management increasing throughput which degraded the ability of the operators to do their jobs effectively.
- Layers of protection aren’t just about instruments. In this case there were multiple civil / structural layers of protection that failed also. Concrete bund (dyke) around the tank was to contain the spill. Built only 3 years before, so relatively new. Because of damage from the fire it leaked through joints and around pipe penetrations leading to catastrophic failure. Bund also contained two other tanks, which is a fairly common. So regardless of whether the bund failed, those other two tanks full of gasoline were going to be exposed to the fire. Site lacked tertiary containment. Once the bund was breached, liquid entered storm water drains and spread across the site. Fuel was able to enter fire-water lagoon and rendered it useless. The fire pump house was flooded when fuel and fire-fighting liquids overflowed the lagoon and eventually flowed offsite further impacting the public. All of our disciplines are important in preventing incidents like this.
- Read the bullet points.
- All sounds pretty simple, right? Just buy instruments, buy valves, buy control systems, and make them all work together. It’s a common misconception. Often the actual specification, procurement, and vendor document review will account for only about 1/4 to 1/3rd of our design budget. There’s a lot of other things we do behind the scenes that total up to the rest.
- Before we go into what I&C does, first we’ll discuss a couple things that I&C in OGC does not do. Sometimes a perception that we do these things directly.
- Both of these require a much different set of skills than doing engineering and design. Most companies who do this well specialize in it. We would not be competitive with them on cost. Re. programming, in our industry there are many different systems in use, with systems dating back to 1975 – when DCS was first released by Honeywell and Yokogawa – still in operation today. Every variation of hardware, and every version of software, has different programming needs. There would be a massive investment required in physical hardware, software, and training to be able to service all these common variations. Most programmers also tend to be highly specialized, with very limited and targeted skill sets. It’s not unusual to hear someone say “I build graphics for Honeywell TDC-3000 and Experion”, and that’s all they do. They don’t do logic, configure points, worry about networks, or even do graphics on systems other than those two they mentioned. Few individuals acquire all the skills needed to take care of all the needs of a single system, let alone many variations. It is very resource-intensive.
- C/S/A generally no direct interface unless we have a building
- What does I&C produce, what information do we need, and why do we do it in a certain order?
- These are roughly listed in the sequence in which we’d do them
- We’ll go through details on each of these and look at examples of most of them
- Compressors can be the manufacturer’s off-the-shelf design, or like a control system that has a compressor attached to it, or anywhere between those extremes. Fired equipment: Boilers and thermal oxidizers generally maximize equipment vendor’s scope for NFPA compliance. Designs tend to be standardized. Refinery heaters generally minimize involvement because they are not very good at it. Every heater is totally customized.
- BMI is involved on very few of these specs because each one tends to be highly customized, one-of-a-kind. Often written specs with no data sheets provided, or for things like analyzers will be multi-page data sheets rather than standard single page. Multi-discipline impacts include input into specifications (piping, structural, electrical, etc.), needs for power, interface points with piping, foundations, etc.
- For normal items, we create a spec package with a data sheet for each item – applies to next two categories, but not necessarily the previous category Top half tends to be general information plus process data
- Bottom half tends to be instrument or valve specifics and notes
- Relief valves often occur late because process needs detailed info on layout, mechanical equipment, and control valves to be able to size them – so that’s usually among the last process data we receive. We realize it’s very important to piping both dimensionally and because of relieving forces for stress analysis, but schedule is almost always compressed for them because it has to be. BMI is involved on many of these specs already, may be future opportunity to increase involvement. Most are custom engineered for the application, not much repeatability so we have tended to keep in U.S. where we can work more effectively with the suppliers.
- Thermowells fall in between the last two categories – more important than a pressure gauge, but less important than a valve or flow meter. BMI does the majority of specs in this category – they tend to be repeatable with large quantities Even the simplest items require engineering knowledge to make proper selections from the catalog, but the components are standardized. Flexible scheduling allows more important activities to be prioritized so that “getting all materials on site” doesn’t become a distraction. More on this later. Virtually all items require review and approval of vendor drawings and documents.
- BMI performs most of the index work
- BMI performs most of the index work
- Usually shared responsibility between U.S. and BMI (U.S. owns and leads, BMI assists) Looks pretty much like the instrument index but with different fields listed.
- Most clients have standard details to choose from A few custom details often needed BMI usually does most of the selection work as part of the instrument index
- This one shows a transmitter process connection and support in one. Usually have individual details for supports, process connections (which show trace and insulation where present), electrical connections.
- Instruments without wire appear on piping isometrics only, not on location plans 3D model is used to convey in-progress design between disciplines Majority of work by BMI, working on methods to automate more of the work
- 3D model is used to convey in-progress design between disciplines Majority of work by BMI, working on methods to automate more of the work Instruments without wire appear on piping isometrics only, not on location plans
- Majority of work by BMI
- Majority of work by BMI Fiber optic patch panel drawings are similar
- Majority of work by BMI Left side is typical of junction boxes or marshalling panels Right side is typical of control system I/O wiring
- Little involvement by BMI
- For most clients the narrative is just a text description of how the controls are intended to work. For some items we may draw a diagram showing how the logic should work. Some clients like for additional information on the controller configuration to be provided. This is an example of a C&E.
- Duration of FAT is usually a few days to a week. For graphics and programming frequently is multiple weeks of work. We are looking for I&C issues. If there is structural steel, pipe welds, 480V power, and similar items included we need other disciplines and possibly also supplier quality to attend as well. FAT not performed on valves, transmitters, or gauges unless there’s a project-specific need
- Majority of work by BMI
- Majority of work by BMI
- Black boxes often include lube oil systems, mechanical seals, alarms for transformers / buildings / heat trace panels / Z-purges for area class Often if the cable schedule is seen to be changing a lot, this may be the culprit Affected documents will be instrument index, I/O list, location plans, wiring diagrams, loops
- Could be due to a schedule that wasn’t realistic from the outset – stemming from an overly optimistic IPPM – rather than due to change or late information Need to make sure disciplines are aligned on dates, sometimes electrical and I&C dates get offset from each other as schedule is developed and changes Also creates problems with progress tracking – get behind and can’t do much to catch up.
- While in the warehouse they may get “borrowed”, damaged, or even have the standard warranty expire before ever being installed Examples of items that get deferred to work on these specs are cable schedule / wiring design, identifying misc. air users for piping, making plans to deal with the “black boxes” on P&IDs, instruments that need power or heat trace If we schedule these for late in the project, then if we have time and staff to accomplish them early we’ll get ahead of our progress curve. On the other hand if we schedule it early and we let it slip (because it isn’t important yet and other things are) then we get behind on progress. The only way we can catch up is to work on these specs that aren’t that important.
- What questions are there about I&C? Are there problems you’ve had repeatedly that we didn’t touch on?