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From CAD User AEC Magazine Vol 22 No 1 - JANUARY/FEBRUARY 2009

AutoCAD P&ID automates time-consuming, repetitive tasks, and improves operating efficiencies, as Tenix Alliance discovered

Antipodean company Tenix Alliance designs, builds, operates and manages water and wastewater treatment plants for corporate and business customers. Based in both Australia and New Zealand, they have been, since the early 1990s, one of the leading providers of design, construction, maintenance, operation and asset management services to the water, electricity and gas industries.

Sewage and Water treatment plants use complex processes, and to help define the layout of a plant, and its instrumentation, the very first design deliverables that need to be produced are the Process and Instrumentation Diagrams. They are referred to throughout the plant design, construction, commissioning and operation. David Callegari, Chief Draftsman at Tenix Allinace explained that "The P&ID is the first thing any designer goes to, so they need to be a completely accurate record of every piece of equipment, valve, pump, motor, instrument and tank on site." The documents also form the basis for procurement of major equipment, valving, pipework and instrumentation.

Up to the middle of 2007, Tenix Alliance, like many other companies, produced its P&IDs by hand, using standard AutoCAD software. Even with that, it was a long and laborious task, ensuring that the documents were accurate. Callegari explained that when the drawings were finished, the engineers would have to manually count the number of components and place the data on a spreadsheet -
time consuming and tedious if they were to avoid errors!

The company decided that it had to automate the process, and in August 2007 evaluated a range of P&ID applications. They selected AutoCAD P&ID, an application built on the AutoCAD platform, and using features familiar to all drafters. AutoCAD P&ID introduced additional features developed specifically for P&ID drafters, streamlining common tasks, and providing direct access to P&ID components and line information.

Assisted by local CAD supplier KarelCAD, Tenix Alliance downloaded a trial version, and discovered that they could deliver their documentation in half the time it would normally take. As its drafters created the drawings, they could also generate reports directly into MS Excel spreadsheets, and engineers could verify component lists. If they made changes to the spreadsheets, these could be imported back directly into the diagrams.

As Tenix was already an AutoCAD user, the learning curve after taking AutoCAD P&ID on board wasn't difficult. With the help of KarelCAD they were able to ensure that the implementation went in smoothly. Automating the many manual and repetitive tasks reduced the time taken to create P&IDs significantly. "Using the old way" said Callegari, "a large water treatment plant took about six months. Now it only takes three."

"Drafters found it much easier to revise and update drawings. If the engineers told us we needed a bigger pump, we just substituted items! It became a simple search and replace. And, instead of manually counting the number of pumps or valves in the diagram, the engineers just run a report and have all the information they need at their fingertips. That cut the total engineering time from two months to about two weeks", he added.

The reports, and the ability to automatically import changes, give the engineers a much better chance of picking up on errors - and procurement is 100% accurate. And after construction, AutoCAD P&ID reports can be imported directly into SCADFA Systems.

AUTOCAD P&ID 2009

Tenix Alliance were users of the first release of AutoCAD P&ID. They are now into the third release, based again on AutoCAD 2009, rolled out earlier this year. It adds new features designed to further the automation process, and the re-use of existing data. It also brings some improvements in the import and export procedures, especially the export of P&ID drawings to vanilla AutoCAD, so that they can be used by design and other engineers.

It also gives P&ID drafters the ability to customise their own data management, and to validate their P&ID drawings. The principal function of the process, though, is for components or properties within the plant to be assigned values relative to their position and function within the plant. This is the automation part of the process, whereby acquisition rules enable a property to acquire its value from another property - the source being another class, project or drawing property.

Of course, they have to be connected - a valve, for instance, acquiring its value from a pipe-line, because they are in a one to one relationship, whilst a tank and a furnace have no direct link, and cannot be used to set up acquisition rules between AutoCAD P&ID automates time-consuming, repetitive tasks, and improves operating efficiencies, as Tenix Alliance discovered them.

You can override value acquisition, but once set up, it has the benefit of maintaining consistent tagging in the P&ID drawing. The tag formats are based on acquired properties, and are updated automatically throughout the project when source values are changed - or components are replaced.

The Data Manager configurator is a useful tool that allows drafters to set up and browse the data according to their particular needs, setting up class hierarchies that reflect their industry. It's simple to use - the Data Manager Configuration tool in the Project setup tree lets you enter a name for your view and to select its' scope. Open a New level to select properties to be displayed in the DM tree and repeat this process for the number of levels you want - to cover manufacturers, model number, suppliers and engineering items etc.

The property based tree that you have created will appear in the Data Manager list, with detailed information on each PnPID in an adjacent pane.

IMPORT AND EXPORT

We spoke about Tenix Alliance's connections with Excel spreadsheets. AutoCAD P&ID 2009 lets you continue to export P&ID data to spreadsheets, but now also as comma separated values (.csv files). Data can then be edited using either Excel or a text editor and imported back into AutoCAD P&ID, where it is highlighted in the Data Manager for user acceptance or rejection.

To share P&ID data with other applications, you need to configure custom export and import settings and external data mapping, transforming P&ID class and property data to match that of the other application - and vice-versa for import of data.

P&ID files can also be exported to AutoCAD in DWG format, maintaining the fidelity of the drawings when you view or plot in the application. Export converts all P&ID components and annotations to AutoCAD blocks, and schematic lines to lines.

AutoCAD P&ID 2008 users are able to migrate their drawings or projects to AutoCAD P&ID 2009 ensuring complete compatibility with the later version. Whichever version is opened, a Migration Wizard is launched, facilitating the process. But users of the 2007 version have to migrate to P&ID 2008 before they go on to 2009!

DRAWING VALIDATION

Automating the production of P&ID drawings enables drafters to maintain absolute accuracy throughout. That applies not only to the properties in the drawing, but also to the fidelity of the drawing itself, and this is handled by P&ID Drawing Validation that checks common errors, such as non-terminating lines and flow direction conflicts.

In the Project Manager users can right- click the Validation Settings and specify the error types that need to be trapped, which includes, besides the above, P&ID objects, size mismatches, spec mismatches, unconnected components, orphaned annotations and a number of other errors. Drafters can choose to validate a single drawing or all of the drawings in a project producing a Validation Summary which they can then act on to correct the errors.

CONCLUSION

P&ID documentation is rather a specialised field, but the application reflects the use of AutoCAD 2009 as a base product that can be built on to suit the needs of specific industries. Assistance in implementing may also require the assistance of Autodesk partners that also specialise in these fields - such as Excelat CAD in the UK, who supplied me with the information on Tenix Alliance and the background to AutoCAD P&ID 2009. www.excelatcad.com

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