Shutdowns advancing

For gas turbines, especially the more advanced high-temperature gas turbines, the oil of choice should be synthetic oil, since synthetic oils have a high flash point. Gas turbine lubrication systems should be run for about 20 minutes after shutdown since maximum temperatures are reached after 10 minutes of shutdown especially in the bearing area. Most gas turbines are also on turning gear to avoid sagging in the shaft. Mineral oils can be used for the compressor. It is not uncommon to have two types of oil in a petrochemical plant. Mineral oil costs much less than the synthetic oil. 

This means that parts must be ordered in advance for the turnaround and other work must be planned so that the whole operation may proceed smoothly and without holdups that could have been foreseen. This usually means close collaboration with the manufacturer or consultant and the OEM (or specialty service shop) so that handling facilities, service men, parts, cleaning facilities, inspection facilities, chrome plating and/or metaliz-ing facilities, balancing facilities, and some cases even heat treatment facilities, are available and will be open for production at the proper time required. This is the planning, which must be done in detail before the shutdown with sufficient lead-time available in order to have replacement parts available at the job site. 

The applicable code procedures should be followed, particularly in regard to instrumentation. On an existing plant, this will require planning in advance of a scheduled shutdown. The pressure and temperature tap locations and installation details can all be developed with the compressor running. All details must be followed. When a drawing states, deburr, do not chamfer that is exactly what it means (see Figure 10-7). 

Atkinson. S. A., 1996, PSA-Operations Synergisms for Advanced Test Reactor Shutdown Operations PSA, Proceeding of the Int ——1 Topical Meeting on Probabilisl ety Assessment, Park City, Utah, pp 600-6 29-Oct. 3. 

Control systems will play a key role in future distributed plants ]139,145]. As a rule of thumb, plants will be smaller and simpler, but the control systems will be much more advanced, of a standard not known today. Plant personnel for operation and managing will ultimately no longer be required, except for start-up, shutdown, and services. This is a shift from a regulatory to a servo role, supported by a sophisticated sequence control. Control is needed for safety issues, operability, and product quality control. Sensors have a central role to provide the information needed for control and modeling and simulation is needed for process models. 

Reduction of the downtime of the structure (hence minimizing productivity losses) and shutdown for repair and renovation and advancement of the time when the structure can be put to use. 

Safety interlocking and shutdown systems require detailed test procedures based around the design docmnentafion (e.g., cause-and-effect charts, binary logic diagrams) that must be formulated and agreed on in advance. 

This transition to development therefore calls only for applied chemical research from developers. It can mark a shutdown of the exploratory efforts that led to finding the clinical candidate. Chemical developers advance the chosen compovmd without seeking a pharmacologically superior substance... 

In determining the density of air flow, it was assumed that the burning fiont advanced radially. These calculations indicate that beginning in about 1970, the density and air flow dropped below the critical. However, in Experimental Section I the density of air flow along the headers of the burning front was not uniformly distributed. As a result, the air flow formed "a tongue" "in one direction, namely in the direction of production well 832. Towards the end of 1972, it was almost reaching the bottomhole of this well so that the well had to be shutdown. 

Preventive maintenance is an interval-based surveillance method in which periodic inspections are performed on equipment to determine the progress of wear in its components and subsystems. When wear has advanced to a degree that warrants correction, maintenance is performed on the equipment to rectify the worn condition. The corrective maintenance work can be performed at the time of the inspection or following the inspection as part of planned maintenance. The decision of when to perform the corrective repair related to PM inspections depends on the length of shutdown required for the repair (Tompkins 1998). 

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