Maintenance process equipment

Sewerage and Refuse Sanitation and Maintenance Process Equipment... 

Figure 12 shows the plan and elevation views of a process unit piping (9). A dmm is supported off the piperack. Heat exchangers are located far enough back from the support columns so that they are accessible and their shell covers can be removed. Pumps are located underneath the piperack, but sufficient room is provided for maintenance equipment to access the motors and to remove the pump if necessary. The motor is always oriented away from the process equipment and located on that side of the piperack. Instmment valve drops are shown supported from the columns. The instmment trays themselves mn on the outside of the support columns. Flat turns are only made from the outside position of the piperack. Nozzle-to-nozzle pipe mns are made whenever possible. Larger lines are located on the outside of the piperack. Connections to nozzles above the rack are made from the top... 

Shutdown. Written procedures for normal, as well as for emergency, shutdowns should be prepared, rehearsed, and kept up-to-date. Operating supervisors must be responsible for leaving the process equipment in a safe condition or preparing plant equipment for maintenance work. 

Additional operations essential to commercial bauxite processing are steam and power generation, heat recovery to minimise energy consumption, process liquor evaporation to maintain a water balance, impurity removal from process liquor streams, classification and washing of ttihydrate, lime caustication of sodium carbonate [497-19-8] to sodium hydroxide [1310-73-2] repair and maintenance of equipment, rehabiUtation of mine and residue disposal sites, and quaUty and process control. Each operation in the process can be carried out in a variety of ways depending upon bauxite properties and optimum economic tradeoffs. 

There is also a distinct advantage in maintenance. When a problem with a phase is discovered and the phase logic is corrected, the correction is effectively implemented in all recipes that use the phase. If a change is implemented in the processing equipment, the affected phases must be modified accordingly and then thoroughly tested. These modifications are also effectively implemented in all recipes that use these phases. 

Introduction Review and audit processes are used in the chemical process industry to evaluate, examine, and verify the design of process equipment, operating procedures, and management systems. These processes assure compliance with company standards and guidelines as well as government regulations. Reviews and audits can encompass the areas of process and personnel safety, environmental and industrial hygiene protection, quality assurance, maintenance procedures, and so on. 

Blocked outlet. Operation or maintenance errors (especially following a plant turnaround) can block the outlet of a hquid or vapor stream from a piece of process equipment, resulting in an overpressure condition. 

Incorrect information can result if the probe is made of the wrong material and is not heat treated in the same way as the process equipment (as well as because of other problems). The probe must be as close as possible to the material from which the equipment of interest is made. Existence of a critical condition, such as weldments or galvanic couples or occluded cells in the eqmpment of concern, makes the fabrication, placement, and maintenance of the probes and monitoring system or critical importance, if accurate and useful data are to be obtained. 

Other information may also benefit the PHA. Standard operating procedures for processing equipment, safe work practices, maintenance or job safety analyses, emergency response plans could be appropriate review items for some PHAs depending upon the toll. 

The hazard identification step of the QRA typically requires the greatest involvement of plant personnel. For an existing process, only plant personnel know the status of process equipment and the current operating and maintenance practices. Excluding those personnel from the hazard identification step increases the chance of overlooking important potential hazards. For accurate results, the QRA team must have access to this information. 

Increased maintenance cost for process equipment due to safety requirements (for example, safety permits, cleaning and purging equipment, personal protective equipment, training, and restricted access to process areas). 

In addition to the fixed capital investment needed to purchase and install process equipment and auxiliaries, there is a continuous expenditure referred to as operating cost, which is needed to operate the process. The operating cost (or manufacturing cost or production cost) includes raw materials, mass-separating agents, utilities (fuel, electricity, steam, water, refrigerants, air, etc.), catalysts, additives, labor, and maintenance. The total annualized cost of a process is defined as follows ... 

The nuclear equipment failure rate database has not changed markedly since the RSS and chemical process data contains information for non-chemical process equipment in a more benign environment. Uncertainty in the database results from the statistical sample, heterogeneity, incompleteness, and unrepresentative environment, operation, and maintenance. Some PSA.s use extensive studies of plant-specific data to augment the generic database by Bayesian methods and others do not. No standard guidance is available for when to use which and the improvement in accuracy that is achieved thereby. Improvements in the database and in the treatment of data requires, uhstaiui.il indu.sinal support but it is expensive. 

The standard requires suitable maintenance of equipment to ensure continuing process capability and to identity keg processes and provide appropriate resources for machine/equipment maintenance and develop an effective planned total preventive maintenance system. 

The standard requires maintenance of equipment to ensure continuing process capability in clause 4.9.1(g) and in clause 4.9.3 requires the supplier to maintain or exceed process capability or performance as approved via customer part approval process. 

ISO 9001 covers the design, purchasing, handling, and measuring equipment activities in the appropriate clauses. The maintenance addressed in clause 4.9 relates only to processing equipment and not to the product that is an output of the process. To provide adequate procedures for product maintenance you will need to ... 

The company concerned normally used slip-plates to isolate equipment under repair. On this occasion, no slip-plate was fitted because it was only a steam line. However, steam and other service lines in plant areas are easily contaminated by process materials, especially when there is a direct connection to process equipment. In these cases, the equipment under repair should be positively isolated by slip-plating or disconnection before maintenance. 

Process and equipment integrity Maintenance process and equipment integrity contributes to exposure control at the same time as it enhances process safety... 

The Chemical Process Industry (CPI) uses various quantitative and qualitative techniques to assess the reliability and risk of process equipment, process systems, and chemical manufacturing operations. These techniques identify the interactions of equipment, systems, and persons that have potentially undesirable consequences. In the case of reliability analyses, the undesirable consequences (e.g., plant shutdown, excessive downtime, or production of off-specification product) are those incidents which reduce system profitability through loss of production and increased maintenance costs. In the case of risk analyses, the primary concerns are human injuries, environmental impacts, and system damage caused by occurrence of fires, explosions, toxic material releases, and related hazards. Quantification of risk in terms of the severity of the consequences and the likelihood of occurrence provides the manager of the system with an important decisionmaking tool. By using the results of a quantitative risk analysis, we are better able to answer such questions as, Which of several candidate systems poses the least risk Are risk reduction modifications necessary and What modifications would be most effective in reducing risk ... 

The first step is to determine the types of plant equipment and systems that are to be included in your program. A plant survey of your process equipment should be developed that lists every critical component within the plant and its impact on both production capacity and maintenance costs. A plant process layout is invaluable during this phase of program development. It is very easy to omit critical machines or components during the audit. Therefore, care should be taken to ensure that all components that can limit production capacity are included in your list. 

To facilitate the maintenance of equipment with different performance criteria, written procedures are needed that serve as a record of the process used to evaluate the system s performance. Maintenance by appropriately trained personnel should be performed at regular intervals before equipment parts fail. 

Pipe runs are normally made up from lengths of pipe, incorporating standard fittings for joints, bends and tees. Joints are usually welded but small sizes may be screwed. Flanged joints are used where this is a more convenient method of assembly, or if the joint will have to be frequently broken for maintenance. Flanged joints are normally used for the final connection to the process equipment, valves and ancillary equipment. 

Processes and equipment should be designed to reduce the chances of mis-operation by providing tight control systems, alarms and interlocks. Sample points, process equipment drains, and pumps should be sited so that any leaks flow into the plant effluent collection system, not directly to sewers. Hold-up systems, tanks and ponds, should be provided to retain spills for treatment. Flanged joints should be kept to the minimum needed for the assembly and maintenance of equipment. 

Canyon structure for containment of process equipment, which would be installed and replaced remotely by overhead cranes. This arrangement is most cost effective in that it provides for maximum use of building space since there is no need for space between process equipment Failed equipment can be replaced in less than one day and is then moved to separate maintenance shops within the canyon structure for decontamination and repair. 

During the plant design the safety of process equipment is also recognized by layout. The objectives of layout are to minimize risk to personnel, to minimize escalation (both within the plant and to adjacent plants), and to ensure adequate emergency access. It is also essential to ensure adequate access for maintenance and operations. Plant layout is a crucial factor in the safety of a process plant because of e.g. segregation of different risks, containment of accidents and limitation of exposure. Safe plant layout is designed on the basis of design... 

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