Installation contractor selection

The section entitles a supplier to rely on the safety-related research and testing already done by others. He does not have to repeat it. For example, an electrical contractor who installs electrical equipment such as a circuit breaker can relay on the assurances of the device s manufacturer that it has been made and tested to an appropriate British Standard. The contractor, however, retains responsibility for selecting the correct type of circuit breaker for the application ensuring, for example, that it has adequate breaking capacity for the prospective fault current. However, importers of foreign apparatus must satisfy themselves that the designer s or maker s assurances are valid. 

Quality of installation and the adherence to design specifications of the equipment should be evaluated to ensure that errors during shipping and installation were not made. Often overlooked at this phase are human factors considerations for the construction crew, such as selection of the contractor, training of the crew, lighting, shift work, procedures, and supervision. 

Site construction of the project requires organizing the constmction bid packages, selecting contractors, and writing subcontracts. These contracts include a specific scope of work for the various construction and installation tasks and the implementation of appropriate procedures for expediting the project. An equipment installation document is then prepared for the construction contractor (9). This document verifies that equipment is properly connected to the defined utilities (air, electrical, water, sanitary drains, product, cleaning systems) and that the contractor has a planned schedule of events. Arrival of the equipment will initiate the startup and testing phase for the equipment. 

Work began in June, 1941, but progress was very slow and it soon became obvious that there was no hope of finishing the job by the provisional completion date of 6 July, 1942. The first machine tools were installed in November, with full production achieved by May, 1943. Asked by the Treasury to account for the delay, the Minister of Aircraft Production explained that construction was overseen by contractors directly appointed by the MAP, which was not the usual practice. Such contracts were usually let by the appointed factory operator, but in this case, because no end user had been selected, responsibility fell upon the Ministry. Sir Alexander Gibb and Partners were contracted to superintend the project on the basis of costs plus 2,500 per annum. Gibb s... 

Selection and design deficiencies are probably the most common as well as the most serious causes of problem incineration systems. Reputable incinerator contractors usually make every effort to satisfy specified design and construction criteria and meet their contractual obligations. Operating and maintenance deficiencies can usually be corrected. However, once a system has been installed and started, very little can be done to compensate for fundamental design inadequacies. Major, costly modifications and revisions to performance objectives are usually required. 

In sewerage schemes alternative systems apply. The water companies controlling the sewers are less concerned with material selection for sewer pipes and so the contract to install a sewerage scheme will, in general, leave pipe purchasing responsibility with the contractor. It is then far more likely that pipe will be bought with price as the main factor rather than any other specified property. 

Fig. 10.11a. A number of seams, which were welded using arbitrarily selected welding parameters (non-bold figures), as well as seams, which were welded in accordance with the requirements of the DVS guidelines on landfills (bold figures) were analysed in detail, and melt depth Zq, squeeze force ratio FILq and thickness reduction ratio sJLq were determined from the manufacture couditions and the data points (Z/Zq, VZq) displayed in this graph. The data points are encoded according to the 13 installation contractors that had manufactured the seams on site. Seams produced on landfill constmction sites are almost without exception within the parameter range 0.5 < s, Lo < 0.9 and 0.75 trun < Zo < 0.9 mm to 0.95 mm permissible according to the process model...

The systems engineer can also provide engineering management support during planning, construction, installation, and testing to help qualify and select contractors, resolve problems, explain design requirements, and assure quality workmanship by the contractors and the technical staff. 

Properly selected, located and installed systems, coupled with employee/contractor knowledge of location and the use of these systems, go a long way toward minimizing and in many cases avoiding injuries altogether, says Pennington. 

SQM, as Eoote, initially selected a brine extraction location for its well field where the brine had the maximum potassium and the least sulfate for potash and lithium production, and later a location with the maximum sulfate content for potassium sulfate production (Fig. 1.57). Because of this the plants could initially use the simplest processes and have the lowest capital and operating costs. In the initial operation brine with up to 3400 ppm Li was pumped from the Salar in 40 wells, 28 m deep on a 200-500 m grid, which delivered up to 5280 m /hr of brine to the solar ponds. There were also 13 monitoring wells to follow any changes in the brine concentration and its depth from the surface. The ponds were lined with flexible PVC or reinforced hypalon membranes, and the brine flowed through the sections of the pond system in series. The initial salt ponds had an area of 1.16 million m followed by 3.36 million m for the sylvinite ponds, and later 1 million m of ponds were installed for lithium production. The plant employed 184 people, of which 120 were hired from the sparsely populated local area. Contractors were used to drill and maintain the weUs, harvest the salts, transport them to their respective stockpiles, and reclaim the sylvinite to feed the potash plant s conveyor belt. They also provided all of the miscellaneous trucking needed at the Salar, and transported the potash to Coya Sur or Maria Elena and the concentrated lithium chloride brine to the Salar de Carmen. SQM unloaded the brine and potash, and stacked the later material at its nitrate plants (Harben and Edwards, 1997). 

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