The wiring for a level switch I’d installed in an extremely hazardous area of the plant was wrong on a one-line diagram. After an electrical storm knocked out the power and some instruments, the plant electrician couldn’t figure out the wiring — and the engineer who drew up the diagram had left the company.
Usually I’d spot such an error by following my personal checklist; it calls for me to walk-down the electrical work with the contract electrician who did it. However, the work wasn’t completed until a week before Christmas and we were in a rush. So, I let it go. My only excuse is that I was swamped then.
So, let’s consider a checklist for completing a project. First, before and during construction: 1) create an outline of the work being done on the project — a workflow diagram works well in identifying bottlenecks and decision gates; 2) maintain a contractor/vendor/stakeholders contact list; 3) do an operations/maintenance review — prior to equipment orders, before budgets and schedules are final and, again, during construction; 3) keep constructors informed of deliveries — sometimes, it’s best to re-route items to them instead of the plant — and maintain an accurate bill of materials (BOM); 4) if possible, monitor constructor’s hours daily; 5) inspect any re-tasked or re-used equipment including often overlooked items, e.g., secondary containment, structural steel and units for utilities like air and water; 6) check equipment upon delivery and during installation; and 7) require computer files for all drawings.
After a project, generate as-built drawings but don’t stop there. Walk-down everything — sometimes changes occur during construction that weren’t part of your scope but could affect it and lead to budget over-run. Do this while the project still is fresh in the minds of vendors and contractors. Ensure the construction area is cleaned up. Pull together marked-up equipment specifications and other items into a maintenance package; review it with maintenance so there aren’t any gaps.
The U.S. Occupational Safety and Health Administration (OSHA) imposes certain requirements. Its management of change process dictates updating drawings. Also, OSHA mandates training for operators and maintenance staff.
In addition, OSHA requires periodic review of piping and instrumentation diagrams (P&IDs) in preparation for hazard and operability (HAZOP) evaluations of regulated areas. This can be interpreted as demanding a project engineer review and edit the whole P&ID if the project affects a regulated area. Do it at the beginning of the project; this heads off the common mistake of using the old drawings for demolition and updating only the construction drawings. Start with new as-built drawings and then produce issue-for-construction (IFC) drawings. Avoid the frequent error of not including detail drawings, such as those for instruments, marshaling panels, air, tracing, etc., in your new diagrams.
Another common mistake is not matching up new equipment to old equipment. Include a separate tie-point drawing with the IFCs if the detail drawings for the tie-points clutter things up.
Companies usually don’t allow resources to clean up projects. Instead, a mad rush to prepare for HAZOPs ensues. Also, firms often assign chores like as-built drawings to inexperienced engineers and consultants. The first group tend to misinterpret while consultants getting a flat fee may take shortcuts and miss spotting mistakes.
Pay attention to what goes into a BOM. Strictly speaking, it refers to shipment lists but a BOM also covers items ordered and installed during a project’s construction phase. Some changes will occur, so make a point of keeping the new invoices when they arrive. Also, ensure the invoices are detailed. You want: 1) contact information; 2) the purchase order (PO) number; 3) your asset number — include major equipment and plant location (you should identify everything in your files in this way!); and 4) most importantly, a complete part number — take my advice, check this many times during the order process.
I usually detail valves, pipe, pumps, filters, motors, belts, etc. These require careful itemization before going into the maintenance files. Each major item, like an agitator, should have a one-page summary, i.e., a data sheet with all basic information: model, size, description, impeller detail, etc. Put the sales contact information in a small folder that also includes the winning PO; keep everything else out of sight. Use electronic files and make duplicates to cope with accidental loss or tampering.