Unplanned

Make maintenance planning more flexible, by providing, wherever possible, viable alternatives to unplanned shutdowns and to immediate component replace or repair actions. Increased flexibility of maintenance planning, by conditionally running under surveillance components with potential or incipient stmctural integrity problems, means improved plant availability, reduced energy replacement and maintenance costs. 

Provide procedures to safely handle the unplanned waste generation and/or neutralize off-spec materials. 

The easiest way to prevent many unplanned premature seal failures is to use balanced o-ring cartridge designed seals. Most of the seal manufacturers make models incorporating these design features. 

S = Seheduled outage hours for planned maintenanee F= Foreed outage hours or unplanned outage due to repair. 

Several steps can be taken to maximize the run time for the reciprocating compressor. Since wear is a function of rubbing speed, the piston speed can be kept to a minimum. Chapter 3 made recommendations for piston speed. Reliability problems due to valves are reputed to account tor 40% of the maintenance cost of the compressor. Valves are the single largest cause for unplanned shutdowns. Basically, valve life can he increased by keeping the speed of the compressor as low as practical. At 360 rpm, the valves are operated six times a second. At 1,200 rpm, ihc valves operate 20 times a second or 1,728,000 times in a day. It is not difficult to understand why the valves are considered critical. To keep the reliability in mind, valve type, material selection and application considerations such as volume ratio, gas corrosiveness, and gas cleanliness need attention by the experts. One final note is that while lubrication is an asset to the rubbing parts, it is not necessarily good for valve reliability. 

While not necessarily improving the reciprocating compressor s indi vidual reliability, using spared units does improve the overall plant reliability. With proper monitoring, the compressors may be removed from service in a timely manner for maintenance. If the program is properly administered, unplanned shutdowns can be avoided and a higher plant reliability achieved. 

Identify all possible chemical reactions, both planned and unplanned... 

Defining individual responsibilities and authority alone will not define how personnel relate to one another. Interrelation means to place in mutual relationship, so what is needed is a definition of the relationships between all staff with quality responsibilities. The primary reason for defining interrelationships is to establish channels of communication so that work proceeds smoothly without unplanned interruption. Staff need to know from whom they will receive their instructions, to whom they are accountable, to whom they should go to seek information to resolve difficulties, and to whom information or product should be submitted when complete. 

ASTDR s mission is to prevent exposure and adverse human health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment. 

As with previous, similar exercises, encourage your team to be creative. Like any sound management system, your PSM system probably creates unexpected side benefits over and above those related spedfically to safety performance. For example, the pilot test may have demonstrated that a new system, once installed, enabled the facility to reduce unplanned downtime with better planning and use of preventive maintenance. Or perhaps the pilot test process itself may have helped improve relations between the facility and corporate staff. 

Planned changes should be documented as part of a formal change monitoring process (for example via a quality assurance system). Unplanned changes should be identified during the accident investigation process. 

There were no unplanned releases of hazardous materials this month, and daily emissions were lower than plan throughout the month. 

This report addresses ammonia plant shutdowns over the listed time period in 40 countries. It provides a basis for comparing plant performance area by area leading to better control of reliability efforts while reducing maintenance and unplanned shutdown costs. Data are presented for shutdowns due to power, equipment, instrumentation, feedstock and product inventory control. 

Two failure modes were considered in the study. The first is failure to start in addition to unplanned demands this includes both fast start tests and slow start tests. The failure to run mode includes all failures occurring from the time when load was applied to the DG until the diesel is no longer needed or until the end of the running duration required by technical specifications. 

Under RCRA. each facility must contain a contingency plan designed to minimize hazards to human hetiltli or tlie enviromiient from fires, explosions, or tuiy unplanned sudden or nonsudden release of hazardous w aste or hazardous waste constituent to air. soil, or surface water. The items tliat follow are applicable to each contingency plan. 

Availability and reliability is at a maximum, with no avoidable unplanned downtime. 

The principal economic implications of corrosion of a plant are the initial cost of construction, the cost of maintenance and replacement, and the loss of production through unplanned shutdowns. The initial cost of the plant is influenced by material selection, and a choice of material that is more corrosion resistant than is necessary for the safe operation of the plant over its design life is a very expensive error. This cost involves initial outlay of money, and plants have been built which could never be profitable because of the inappropriate materials selection. 

Items of plant fabricated from stainless steels should be inspected before first use and after any maintenance work or unplanned shutdown. All materials that rely for their corrosion resistance on the presence of an oxide or similar passive layer are susceptible to localized attack where that layer is absent or damaged. Damage is most commonly caused by scratching, metallic contamination (nearby grinding or touching with ferrous tools), embedding of grit and weld spatter. 

A prerequisite to a corrodable material being used is that it is known to have a useful and reasonably predictable life. Planned, or unplanned downtime costs money and the intervals between planned replacements must be of reasonable duration. In practice, the replacement interval is usually conservative at first and then as experience accumulates, the intervals between planned replacements will usually extend. The main reason for choosing a planned maintenance policy is that on a discounted cash flow (DCF) calculation over the life of the plant, the cost of regular replacements including maintenance labour and downtime is less than the extra initial capital cost of a more durable material. 

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