Cálculos de fatiga

D. GIBSON, AVEVA, Cambridge, England

A straightforward, graphical approach, combined with drag-and-drop functionality, enables wiring projects to be designed and change-managed in the simplest way possible.

FIG. 1

INSTRUMENTATION

86

I

graphical views are role-based, so each user sees and interacts with those elements that are of most use to them.

No. 2.—Lack of change manage-ment. While the creation of data is abso-lutely key to the early momentum of a proj-ect, the ongoing challenge is in managing changes to the design and ensuring that the changes are properly reflected throughout the dataset. Often, more cables and con-nections are added to the plan than were originally envisaged, swelling the data considerably and producing a significantly altered design. This complicates the rela-tionships between existing and new infor-mation, forcing a time-consuming and costly estimate revision process.

The instrumentation program comprises three integrated modules that share a com-mon, multi-user database for both design and as-built data. This integrated data envi-ronment enables extensive validation pro-cesses, automatic cross-referencing and link-ing of associated information, and rigorous change control. Change of all kinds can be easily tracked, highlighted and reported on, and its impact automatically flagged (Fig. 2).

No. 3.—Wiring limitations. Wiring design is a multi-phase process, involving loop diagrams, schedules and termina-tions—yet many technologies currently available on the market are unable to inte-grate these procedures into one

applica-tion. The wiring designer has to coordinate design data manually between several dif-ferent applications—an open invitation to error, as well as a seriously inefficient use of a technically skilled individual’s time.

To make things worse, input of data into the wiring design is usually via table and spreadsheet—there is no means of visualizing the relationships and using those visualizations as the logical starting point for the creation and editing of the wiring design. This instrumentation pro-gram, by contrast, requires only one click to enable the user to see a current graphical representation (Fig. 3). There is no need to request an output plot from a designer, which can take many hours of unnecessary work. Within a single application, loop dia-grams, schedules and terminations can all be created and edited from the same visual engineering environment.

No. 4.—Catalog of errors. Catalog changes are one of the biggest causes of design data mismatches in the instrumenta-tion and control universe. Yet they are often an essential way of managing and reducing procurement costs, and so can heavily influ-ence the economic viability of a project.

For example, the purchasing depart-ment might decide on a different supplier for a particular component, causing a change in the nomenclature of that compo-nent and the associated vendor details. The problem comes when these changes are not

accurately reflected across the whole proj-ect—which they rarely are. This can neces-sitate massive rework later in the process.

The instrumentation program provides dynamic catalog management as standard.

Vendor details and component references can be changed any time throughout the project with no need for manual rework.

If a pressure gauge supplied by vendor X is changed in the catalog to a similar prod-uct from vendor Y, identified by a differ-ent part or tag number, these changes will be updated (or will simply show where updates need to be made). This happens automatically across all mentions and instances of the original gauge—in cable block diagrams, loop diagrams, instrument indexes, datasheets, hookup diagrams, ter-mination diagrams, cable schedules, bill of materials, etc. Mismatches between cata-logue data and project execution data, as well as the many expensive hours needed to rectify them, are a thing of the past.

No. 5.—Lack of visualization and reporting clarity. The ability to report on a design at will is fundamental both to progress management and design quality control. Yet with many software packages, reports can only be generated by the use of programming scripts that have to be spe-cially requested and produced—an unnec-essary overhead in time and labor. There is no easy way, in most of the instrumentation software currently available on the market, to quickly build up a picture of the interre-lationships in the project dataset. Likewise, no other vendor currently enables instant reporting on the database revisions to give an understanding of change history.

This instrumentation program is built around user-defined reporting—across schedules, lists, bill of materials, and other data. The simple interface puts the report-ing process back into the engineer’s hands and enables all items, data and documents that share the same tag to be instantly listed.

This graphically shows how changes to one item might have impacts elsewhere in the design. A full audit log of database changes can also be instantly generated—vital for root-cause analysis and risk management.

No. 6.—Scalability price. Database technology is key to effective instrumenta-tion design—the applicainstrumenta-tion’s scalability is directly related to the efficiency of the data-base. Unfortunately, some vendors have taken excessive advantage of this depen-dency. While their application upgrades are usually delivered at no further cost, the

Information is fully auditable and reportable, enabling change to be effectively and safely managed.

FIG. 2

INSTRUMENTATION

87

upgrades to the database that underpins them are often an expensive service. This means that ongoing support and scalability can only be achieved at a very high cost—

the exact opposite of what flexible scalabil-ity should deliver.

No. 7.—Vendor data breakdown.

Like all engineering processes, instrumen-tation and control are dependent on com-ponents provided by a range of suppliers.

Approaching vendors for datasheets on the components they provide is often a hit-and-miss process—the information returned can be incomplete and is typically sup-plied in a number of disparate formats/file types. Designing a prescribed template for the datasheets is not nearly as effective as it might be, as it usually has to be carried out in an unintegrated, third-party application.

This, in turn, means that the responses have to be manually received and adminis-trated, manually followed up when neces-sary, and manually linked to the data in the main design system. Any two or more indi-viduals, equally skilled and experienced, will inevitably perform this task very differently, leading to mismatches and inconsistencies.

Needless to say, these manual processes are also time-consuming and expensive—not what a project manager wants to hear.

No. 8.—Inability to view instru-mentation data in 3D. In many instrumentation and control technologies, there is no integration of the data with the 3D model of the plant. This makes it dif-ficult for engineers and designers to make judgements on spacing, tolerances, buffer zones, clashes and so forth, as well as on quantities and dimensions.

For example, cables come in many dif-ferent types and need to be routed in a way that effectively segregates them by voltage, function, flux, heat dissipation, etc., while economizing on the cable length. This combined requirement is virtually impossi-ble to meet if the user cannot visually model the deployment. This program works with industry-standard Microsoft databases such as SQL Server and (for smaller projects) MS Access. Updates to both the application and the databases are received as a normal part of the licensing process. There is no additional cost. The emphasis is on protect-ing a customer’s investment in data, rather than exploiting it. There is no charge for updates and upgrades with customers on an active maintenance contract, and it has also made massive investments to ensure that the technology works in mixed IT

environ-ments with customers’ existing third-party applications and data types.

The company does not force users to

work with multiple applications that are not integrated. Instead, it enables the cre-ation of datasheet templates within the

The reporting capability is powerful and flexible, producing instant results on screen, as well as in print-friendly format.

FIG. 3

Quest Integrity Group is a dynamic company built on a founda-tion of leading edge science and technology that has innovated and shaped industries for nearly 40 years.

Our asset integrity and reliability management solutions are comprised of technology-enabled advanced inspection and engineering assessment services and products that help com-panies in the refi ning and chemical, pipeline, syngas and power industries increase profi tability, reduce operational and safety risks and improve operational planning.

(888) 557-3363 (888) 893-7030

www.QuestIntegrity.com [email protected] Asset Longevity

Plant & Pipeline Performance

Select 164 at www.HydrocarbonProcessing.com/RS

INSTRUMENTATION

88

I

application itself, in a way that is totally integrated with the rest of the project workflow. These templates can be partially populated by the engineer or designer with information that is already known. This gives vendors a much clearer indication of what information is needed, making their task easier and increasing the likelihood that the datasheet will be completed to the required standard. The content of the data-sheet is easily searchable and reportable. It can be extracted and viewed in seconds, rather than having valuable minutes and hours wasted in attempts to search for it.

3D models are fully integrated with other providers to enable instrumentation data to be viewed in full 3D context. This means that cable data can be integrated into the 3D model straight from the instrumentation program and automated cable measurement, routing and segregation can then be gener-ated instantaneously. Greater control, less rework and enhanced safety and compli-ance, without risky and time-consuming guesswork, can save millions of dollars in design time and material procurement.

No. 9.—Incomplete associations.

Instruments and wiring activities

gener-ate a huge amount of relgener-ated information including data sheets, documents, etc.

Many isolated systems completely fail to link this information together, as it typi-cally comes from both internal and external sources. Engineers and designers, therefore, have to second guess both the nature of the information and its location. Apart from being terrifically time consuming, this also perpetuates the problem of “unknown unknowns” and this is clearly an unsatisfac-tory basis for making informed design and engineering decisions.

The problem is often at its most acute with external documents such as vendor datasheets. With internal documents, the designer or engineer can bring pressure to bear on the situation; he is organizationally connected to the document producers and is regarded internally as a key customer.

With external documents, this dynamic is less relational—and so designers or engi-neers need a different way of bringing authority to their requests for information.

The instrumentation program provides object-based navigation through hyper-links. Related items of data are linked together automatically, no matter what for-mat they are in or where they are physically

located. In a single click, an engineer or designer can view the object and see exactly where all the information that relates to a specific component or design element resides. This reduces not only the direct costs of manually searching for informa-tion (estimated in recent studies to take up as much as 60% of an engineer’s time), but also the less obvious expense, such as when the designer or engineer approaches a col-league to help him find information, thus wasting two people’s time instead of one!

The majority of safety related incidents have also ultimately been related to poor information accessibility, so the ability to diminish this risk substantially is a big part of the benefit that this program brings.

No. 10.—Fragmented bulk data upload. The ability to bulk-upload data at the beginning of a project is key to achiev-ing initial traction. However, the data typi-cally comes from many different sources and in many different formats, and this fragmentation often necessitates the use of several different applications. Piping and instrumentation diagrams (P&IDs), for example, are an absolutely integral part of the instrumentation and control design pro-cess, but they are often not an integral part of the data upload, having to be sourced and integrated independently.

This reliance on a multi-application approach consumes time, effort and money, and increases the likelihood that critical data will be missed or incompletely captured. The program enables complete integration of all data types, including P&IDs. An initial bulk upload creates links and associations between these different types of information. The project benefits from much more rapid traction and the engineers and designers have all the infor-mation at their fingertips in a way that is dynamically managed and updated across the life of the project. HP

The Planning Guide to Piping Design By Richard Beale, Paul Bowers and Peter Smith

300 pages t Hardcover t Pub date: September 2010 t Price: $175 ISBN: 978-1-933762-37-1

The Planning Guide to Piping Design covers the entire process of planning a plant model project from conceptual to mechanical completion, and explains where the piping lead falls in the process along with his roles and responsibilities.

Advanced Piping Design By Rutger Botermans and Peter Smith

250 pages t Hardcover t
Pub date: May 2008 t
Price: $175 ISBN: 978-1-933762-18-0

An intermediate-level handbook covering guidelines and procedures on process plants and interconnecting piping systems.

The Fundamentals of Piping Design By Peter Smith

262 pages t
Hardcover t
Pub date: April 2007 t
Price: $175 ISBN: 978-1-933762-043

Written for the piping engineer and designer in the field, this first part of the two-part series helps to fill a void in piping literature, since the Rip Weaver books of the ‘90s were taken out of print.

To place an order, visit www.gulfpub.com or call +1 (713) 520-4426.

David JS Gibson is the head of product strategy for instrumentation and electrical systems for AVEVA. He joined AVEVA business development in December 1999 after serving 25 years working for a major engineering, production and construction company, formally in the engineer-ing design and then as development project manager for engineering data management systems. He has worked on a variety of engineering projects for various clients in the oil and gas and pharmaceutical industries.

Projects covered a wide range of processes for oil and gas, pharmaceutical, chemicals and polymers and food processing, and he has had experience in all aspects of engineering design. Mr. Gibson attained his manage-ment qualifications from the Open University.