Standard Operating Procedures
Process Technical Services (PTS) has experienced procedure writers that can prepare the standard operating procedures required for your process operators. Modern chemical processing plants and refineries have multiple unit operations connected sequentially. The era of the large single-line plant has complicated the control problems because of the close coupling of units and the sheer size of the plant.
Standard operating procedures should cover three main areas of operation. First are the safety considerations associated with the process. The operator should be knowledgeable regarding the safety hazards associated with all of the process materials used in the process. An operator must be thoroughly familiar with the potential safety and environmental hazards associated with plant operation. He must understand the process flowsheet and have a mental picture of how the plant is structured and how it operates. He must know where the pressure relief valves and rupture disks are located and where the releases will go in the event their operation is triggered by an upset in the process. Finally, the operator must be familiar with the process interlocks and what actions will trigger them.
The second element that needs to be covered in written standard operating procedures is a description of the control system. Some control systems can handle a wide range of operating rates and still provide good dynamic control of the process. On other processes a change in operating rate will require an instrument technician to retune the PID controllers for the new operating rate. It is important that controllers be carefully tuned to the process and kept on automatic as much as possible. Sometimes there are upsets to the process that require controllers to be placed in manual mode to stabilize the units. However, once the upset has past, standard operating procedures should require that the controllers be placed back on automatic.
The third element in standard operating procedures involves specifying the standard operating conditions. These reflect the conditions across the process that provide the best economical operating point for the operating rate selected, and one that will keep the product meeting specification without expending money with over-purification. The operator needs to understand how to best correct for excursions away from the standard operating conditions. There are often several ways that this can be accomplished, but only one of these will prove to be optimum.
By adhering to standard operating procedures it is often easier to spot and diagnose a problem with the instrumentation, or process analyzers. Instability and an inability to stabilize plant operation can be due to a failure of instrumentation, failure of a control valve, or failure of a pump. Familiarity with standard operation provides the operator with the basis for judging the reliability of process analyzer or process laboratory results. Sometimes these sources of process information can be badly in error.
Standard operating procedures are necessary to insure the safe startup and efficient operation of a plant. PTS has the experienced and skilled procedure writers that can create the
standard operating procedures
necessary to provide the operators
with the guidance they need,
and serves also to partially meet the requirements for ISO 9000 certification.