Plot plans construction

Typical Definition Phase (FEL-3) Deliverables These are listed below. In this phase, emphasis is typically on optimizing the best flow scheme and support systems combination. This optimum includes consideration of the plot plan and equipment arrangements for the entire facility. Process optimization cannot be done in isolation. Significant and continuous interaction with operations, maintenance, and construction... 

Definitive estimates. Definitive cost estimates are the most time-consuming and difficult to prepare, but they are also the most accurate. These estimates require preparation of plot plans, detailed flow sheets, and preliminary construction drawings. Scale models are sometimes used. All material and equipment is listed and priced. The number of labor hours for each construction activity is estimated. Indirect field costs, such as crane rentals, costs of tools, and supervision, are also estimated. This type of estimate usually results in an accuracy of 5%. 

Provide project engineering and constructability input to plot plans and equipment arrangement options. 

Figure 7-6 shows a plan of the feed gas compressor area for a 200,000 tons per year ethylene unit. Main pipe runs are also shown. It is an In-Line-Layout with equipment in process flow sequence. The large diameter gas lines directly interconnect process equipment. On the complete plot plan, equipment (including compressors) is arranged on both sides of a central yard in process flow sequence. Pumps are located at their point of suction and are lined up under the yard. A parallel road is arranged to every line of equipment for convenient construction and maintenance access. 

Once the plant location area and plot plans have been chosen, as explained in Chaps. 5 and 7, the specific site must be selected and developed for installation of structures. Preliminary exploration of the subsurface conditions should be done prior to purchase of a piece of land, since foundation construction may be abnormally high if the bearing load of the underground strata is poor, even though the surface conditions appear satisfactory. Topographical maps of the site to establish plant grades and excavation, together with transportation facility locations, frost-line, and water-table information, are other important site data required. Some detailed aspects of these factors will be presented next. 

Reference Markers. Plant layout on the site requires a starting or reference point after the exact location of the property has been determined by permanent property markers already established or by independent survey of a local surveying firm. Markers are usually large-diameter capped steel pipe set in concrete, located outside the construction area, so that directional and elevation data can be taken relative to these permanent posts. One marker is called the zero corner point and all measurements start from there. Plant north and its relation to true north are next set up so that master plot plans can be oriented to the plant site and surveying stakes located in the working area. 

Construction The plot plan is used to schedule the ereaion sequence of all plant equipment, which includes rigging studies for large lifts, constructibility reviews, marshaling, and lay-down areas throughout the entire construaion phase. 

Plot plans are generally developed in stages, from the initial concept to the ftilly dimensioned document at the construction issue stage. 

After contraa award, the proposal plot plan is updated to suit the latest information and is reviewed and approved by the client. This document becomes the basis for the plant layout phase of the projea and is called the planning plot plan. A sample planning plot plan is shown in Exhibit 3-2. On completion of the plant layout phase—when all the equipment has been sized and is in the best position to suit the projea requirements and when all access roads, buildings, and pipe tacks have been located—the plot plan is finally issued for construction. Ihis is illustrated in Exhibit 3-3 as the construaion plot plan. 

The advantages of this type of arrangement are the small amount of real estate required for the plant and the ability to house the facility to suit process requirements or climate conditions. The disadvantages are in the operator and maintenance access and in the construction of the plant. Exhibit 3-8 shows a npical structure-mounted vertical plot plan arrangement. 

This chapter has highlighted some of the principal features involved in the arrangement of process equipment with regard to operation, maintenance, constructibility, safety, and economics. Subsequetii chapters deal with the needs of each equipment item in more detail, thereby offering greater insight to proper equipment location on a plot plan. 

Diagrams Final PFD and P ID, vessel sketches, utility balances, plot plan and elevation diagrams, and piping isometrics. All diagrams are required to conplete the construction of the plant if it is built. 

Planning Have a clear objective for constructing the plot. What is the likely spread of the data Is your scale appropriate ... 

Constructing a control chart is a relatively simple process. Anyone can get started by selecting a measure of queility and plotting it in order of time. When enough data become available, a centerline and control limits can be calculated (e.g., using the individual control limit formulas). Many useful control charts have been developed with this minimal amount of planning. 

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