Bolts maintenance

The other space-saving approach is to use the Kobe (Kobe Steel) type of channel enclosure, which does not have all the external head bolts of typical TEMA Type B or Type C head enclosures. These exchangers require special tools to remove the tube bundles and trained maintenance personnel to do the work. These exchangers should never be located in stmctures because of the need to be able to access the channel from grade as it is difficult to remove the channel cover plate by using special equipment. 

The plug, cage, seat ring, and associated seals are laiovvn as the trim, A kev feature of globe valves is that thev allow maintenance of the trim via a removable bonnet without removing the valve bodv from the line. Bonnets are tvpicallv bolted on but rnav be threaded in smaller sizes. 

Air-Filter Types Air filters may be broadly divided into two classes (1) panel, or unit, filters and (2) automatic, or continuous, filters. Panel filters are constructed in units of convenient size (commonly 20- by 20-in or 24- by 24-in face area) to facilitate installation, maintenance, and cleaning. Each unit consists of a cleanable or replaceable cell or filter pad in a substantial frame that may be bolted to the frames of similar units to form an airtight partition between the source of the dusty air and the destination of the cleaned air. 

This condition is probably misalignment, indicating a maintenance problem. The mechanic should be trained to correct this. Follow correct alignment procedures, as well as correct bolt torque procedures. 

The problem could be maintenance, operation, or design, or a combination of any or all these factors. In all honesty, you should never. see this set of evidence marks because it indicates a lack of control. Now because the mechanic cannot control operational problems or design problems, the first phase to correct this situation is to control the mechanical maintenance factors, like alignment, proper bolting and torque. sequences, be sure shafts are straight and round, and dynamically balance all rotary components. Reinstall the pump and wait for the next failure. Once the maintenance factors are under control, there should appear a clear vision and path to resolve any operational and/or design weaknesses. 

If there were no removable cover on the front end of the exchanger, it would be designated BES." The second nozzle and pass partition in the front end are discretionary depending upon the shell type. Types A and B bolt onto the shell. In type C, the head cannot be unbolted for maintenance. 

Drain valves that are used only occasionally to empty equipment for maintenance should be blanked when not in use. Regular surveys should be made to see that the blanks are in position. On one plant, a survey after a turnaround showed that 50 blanks were loose, each hanging on one bolt. 

No open process or chemical sewer drains should be under or in the drainage zone from a fired process heater since the heater could ignite flammable vapors present in the process/chemical sewer. Where pro-cess/chemical sewer drains are required at a fired heater during cleanup and maintenance, the drain openings should be sealed by a gasketed and bolted cover prior to startup of the heater. 

The alert mechanic informed the operations supervisors of the failures. Operations shut down the furnace. Maintenance mechanics replaced the bolts with the properly-specified high-strength stud bolts prior to any serious releases. 

As illustrated in Fig. 16-2, the caps can be held in place by bolts or by a hold-down bar however, the hold-down bar is seldom used because it interferes with the flow distribution. Since periodic removal or maintenance of the caps may be necessary, the preferred method for holding caps and trays in place permits removal of the caps by one person working in the crawl space above the plate. 

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