Breakdown equipment

For an existing facility it is necessary to review all corrosion, explosion, fire incident, breakdown, equipment/control failure, and maintenance issues. 

If maintenance is performed, there are two principal maintenance strategies preventive and breakdown maintenance. These are not mutually exclusive, and may be combined even in the same piece of equipment. Take for example a private motor car. The owner performs a mixture of preventive maintenance (by adding lubricating oil, topping up the battery fluid, hydraulic fluid and coolant) with breakdown maintenance (e.g. only replacing the starter motor when it fails, rather than at regular intervals). 

Breakdown maintenance is suitable for equipment whose failure does not threaten production, safety or the environment, and where the cost of preventing failure would be greater than the consequence of failure. In this case, the equipment would be repaired either on location or in a workshop. Even with this policy, it is assumed that the recommended lubrication and minor servicing is performed, just as with a motor car. 

Preventive maintenance includes inspection, servicing and adjustment with the objective of preventing breakdown of equipment. This is appropriate for highly critical equipment where the cost of failure is high, or where failure implies a significant negative impact on safety or the environment. This form of maintenance can be scheduled on a calendar basis (e.g. every six months) or on a service hour basis (e.g. every 5,000 running hours). 

Cost Calculation. The main elements determining production cost are identical for fine chemicals and commodities (see Economic evaluation), a breakdown of production cost is given in Table 2. In multipurpose plants, where different fine chemicals occupying the equipment to different extents are produced during the year, a fair allocation of costs is a more difficult task. The allocation of the product-related costs, such as raw material and utiHties, is relatively easy. It is much more difficult to allocate for capital cost, labor, and maintenance. A simplistic approach is to define a daily rent by dividing the total yearly fixed cost of the plant by the number of production days. But that approach penalizes the simple products using only part of the equipment. 

A PPM program is needed to avoid equipment failures, utiHty outages, and production intermptions. From a cost savings angle it is extremely important to do preventive maintenance in order to avoid breakdowns. Periodic inspections and a good lubrication program uncover conditions that could lead to breakdowns. When problems are found eady, they can be taken care of without work intermption and costly repairs. Sometimes faciHty managers are so afraid of downtime that preventive maintenance is done too often. In other cases production does not allow adequate time to provide proper maintenance. 

Monitoring by Electromechanical Instrumentation. According to basic engineering principles, no process can be conducted safely and effectively unless instantaneous information is available about its conditions. AH sterilizers are equipped with gauges, sensors (qv), and timers for the measurement of the various critical process parameters. More and more sterilizers are equipped with computerized control to eliminate the possibiUty of human error. However, electromechanical instmmentation is subject to random breakdowns or drifts from caUbrated settings and requires regular preventive maintenance procedures. 

The method uses a breakdown of costs for a typical chemical plant installed in the United States, as shown in Fig. 9-44. Costs of equipment, appurtenances, construction, and engineering with material and labor separate are given as a percentage of total installed United States costs. The four components of cost are defined as follows ... 

Capital Costs A typical medium-scale RO seawater plant might produce 0.25 mVs (6 MGD). For a plant with an open sea intake, seawater salinity of 38 g/1, and conversion of 45 percent, the overall cost woiild be 26.5 miUiou (1996). A capital breakdown is given in Table 22-18. Capital charges are site specific, and are sensitive to the salinity of the feed. A plant of this size would likely contain six trains. For seawater RO, the Best estimate for the slopes of the family of lines in Fig. 22-55 is —0.6 for the equipment and 0.95 for the membranes. Capital charges, shown in TaBle 22-19, usually dominate the overall economics the numbers presented are only an example. Seawater economics are based on Shields and Moch, Am. Desalination Assn. Conf. Monterey CA (1996). 

A quality service can be provided only by reliable equipment. This section seeks to ensure that effective routine inspection and maintenance programs are in place in order to detect defects before they cause accidents or breakdowns. 

Combining the practice of preventive maintenance and total quality control and total employee involvement results in an innovative system for equipment maintenance that optimizes effectiveness, eliminates breakdowns, and promotes autonomous operator maintenance through day-to-day activities. This concept known as Total Productive Maintenance (TPM) was conceived by Seiichi Nakajima and is well-documented in his book Introduction of TPM and is highly recommended reading for all involved in the maintenance area. 

Is it reasonably foreseeable that an aeeidental leakage, spill or diseharge eould oeeur (e.g. following an operating eiTor or breakdown of equipment or failure of a eontrol measure) ... 

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