March 15, 2007

Focus on O&M (March 2007)

PLANT MANAGEMENT

Writing sensible start-up and shutdown procedures

There's a fine line to walk when writing O&M procedures because you're writing for two separate "customers." One is the operator who will have to use the procedures. Because operators live with the plant every day (and because you may have trained them), you don't want to insult their intelligence by making instructions unnecessarily detailed.

The other customer is an insurance inspector or regulator who may read the procedures when seeking to determine why a boiler exploded or a chemical spill occurred. For this customer, procedures need to be as specific and detailed as possible.

Following are some helpful hints for writing useful start-up and shutdown procedures:

• Arrange them in checklist form, with numbered steps. Put lines or boxes for the operator to initial and for recording when each step was completed. Time stamps provide an important record if anything goes wrong.
• Use a note to explain that each numbered step must be completed before moving on to the next one. A step is different than a note. Because notes are reminders or comments that don't necessarily have to be completed, they should not be numbered. Example of a note: "Monitor drum levels closely as steam pressure begins to rise."
• Keep completed checklists in a historical file for a reasonable time. One year is usually sufficient.
• Avoid vague statements such as "Check the drains." Check them for what? Leakage? Whether they're open or closed? What position should they be in?
• To the extent possible, quantify parameters. Don't say "Check that oil pressure is normal." Say, "Check that oil pressure is between 20 and 65 psig."
• Integrate notes describing indications that the operator can expect to see after completing each step. Example: "Step (1) Turn the start/stop switch to 'start' and release. Note: The 'starting cycle' green light should come on."
• Be specific about where to execute each step. Does the operator start the gas compressor locally or from the distributed control system (DCS)? Can he rely on a DCS indication that the cooling tower fans are running, or must he visit the tower to confirm that with his own eyes and ears? Usually, local indications are better than remote ones, but it's not always feasible to check something locally.
• Minimize acronyms, and use plain-word descriptions of components and valves. Don't say, "Open AOV-16." Say, "Open the No. 16 Air Ejector Valve (AOV-16)."
• Conservation may be a personal virtue, but don't try to save a tree by minimizing paper. Print the checklist in large, double-spaced type so it's easy to read.
• Don't use too many words for any one step. An instruction should be no more than a few sentences, not the length of a magazine article.

Open mind time

At many plants, operators who suggest improvements to procedures may have to fight through red tape to get them implemented. For example, they may have to fill out a complicated, three-page discrepancy form, send it up the corporate ladder, and wait months for a response. Or they may be asked to dial a phone number and leave a recorded message, which administrative assistants then try to interpret and type into memo form for submittal to their department head.

At least one utility plant in Florida has found a better way. Operators there can go to a computer keyboard, open a custom-designed database of operating procedures, and submit their suggested change. Comments are immediately posted to the procedure writers, who review the file three times a week. This usually generates a rapid response. But if it doesn't, the comments remain posted right on the procedure for other operators to read.

The last step in every procedure should be a physical examination of the equipment. A veteran operator can ascertain much about a steam turbine by leaving his warm, cozy control room and walking around the unit a few times, using all five senses—and a little bit of the sixth. Old-timers know that only when standing in front of an operating machine can the complexities of the real world—the stuff that computer screens and computer print-outs ignore—be appreciated.

To their detriment, some plant managers carry this idea to the extreme and prescribe rigid operator rounds, including the punching of mechanical time clocks to record their travels. With today's powerful DCS keeping a watchful eye, all that is accomplished by such archaic practices is the completion of forms that often end up in some rusty file cabinet without ever seeing the light of day. Veteran managers realize the morale-sapping futility of dictating their operators' every step, and allow them some flexibility and creativity during the watch.

Once people begin doing everything "by the book," operations quickly go downhill. Workers lose interest and become bored; they forget why the company does things certain ways; and they begin to feel more like cogs in a machine than integral parts of a vibrant team. Don't let institutional procedures take the place of human judgment.

A good compromise is to require that plant rounds—a time-honored power plant tradition—be made at least twice per shift, to keep operators alert and to get their "eyes and ears" out where they can do the most good. At competitive power plants, operators even perform minor maintenance tasks—such as such as repacking valves, oiling equipment, testing feedwater and cooling water, housekeeping, and painting—during the rounds. Prepared "rounds sheets," which list specific equipment to be checked, can help maintain consistency between shifts. But like so many other formalities in the plant, they are most effective if their users—operators—are involved in developing them.

Once rounds sheets are developed, you can easily take the next step and create oil and grease sheets. Sometimes these sheets are color-coded, with each color representing a specified type of oil or grease. This minimizes the chances of an operator pumping lightweight grease into a heavyweight application in a state of semi-consciousness at 3:00 a.m.

As an aside, one of the most commonly missed components on oil and grease sheets is the valve or damper actuator. These mechanical devices often sit in one position for extended periods of time. Without routine greasing and cycling, they may fail to operate when needed.

Keeping a written logbook goes hand-in-hand with the time-honored tradition of making rounds. And, like the rounds, a professionally maintained logbook is no less important in this age of automated control rooms. Besides serving as a valuable troubleshooting history and legal document, the logbook encourages a thorough turnover of the shift from one operator to another.

If you've worked in a power plant for any length of time, you know that the logbook is a source of great pride among fellow operators. It's usually a hard-bound, sequentially numbered journal into which the operator documents the events of his or her shift, beginning with the formal, but important words: "Assumed the watch." Other entries that operators should make include:

• The general condition of the plant when the shift changes.
• Changes to operations or equipment made during the shift.
• Equipment taken out of service or locked-out/tagged-out.
• Start/stop times of special events, such as system start-ups and tests.
• The arrival time of enforcement officials, insurance inspectors, and contractors.