Access Ways, and Paving

For maintenance and safety, the principal access to and from most process units is by auxiliary roads, Ideally, the unit battery limits should be positioned 50 ft (15,000 mm) from the centerline of the main plant roads. This allows adequate space for ditch drainage and firefighting facilities and avoids obstructing roads when such items as heat exchanger tube bundles are removed. Access ways or spur roads should be provided within the unit for access to items that require servicing or for components that require removal for off-site repair. Clearance according to project specification should be provided over roads and ac- 

The previous sections have outlined the information required to locate equipment and the general content of the typical process unit. At this stage, the plant layout designer should prepare a sketch of the unit configuration and a line run to confirm that the equipment is positioned for the most favorable piping interconnection. The line run can be prepared by dia- 

EXHIBIT 3-22 Typical Pipe Rack in a Vertical Arrangement 

The final step in the plot plan arrangement is to space equipment and supporting facilities for operator and maintenance access, safety, piping flexibility and support, and platforming requirements. At this stage, the layout designer must rely on experience because the final information is not available for calculating 

EXHIBIT 5-23 Typical Process Unit Road and Paving Arrangement 

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