Pipe racks, processing facilities

A flammable hydrocarbon gas that is lighter than air is processed at a small facility. An office building is located 75 ft (15 m) from the processing equipment. Because of the size of the facility, no pipe racks or other significantly sized equipment are in the area that can create confinement or congestion if a release occurs. Further, the flammable gas is processed at low pressures and ambient temperatures. 

Pipe racks normally divide a facility into major areas. For economy and process efficiencies the piping arrangement is typically a central corridor in any facility. On either side of this pipe corridor or rack the process units are provided buy its nature divides the facility into units or process areas. 

Outside battery limit (OSBL) defines the work and responsibilities outside the battery limit. The OSBL includes auxiliaries required for the chemical process unit, including tank storage for feedstock and refined products, waste treatment, cooling towers, flares, and utilities that are not included in the battery limit but are required for the unit. Also included are the pipeways, racks, and sleepers, which are used to convey all of the utility s interconnecting process piping to and from the processing facility... 

Pipe racks within vertically structured or housed facilities cannot be defined as easily as for inline arrangements, because the equipment is usually located on several levels. The venical units are usually fed by conventional pipe racks at established elevations entering the structure at a designated area. Once inside the structure, piping should be routed in an orderly manner according to economic, constructibility, and support requirements. Exhibit 3-22 displays a typical process structure. 

For small facilities (e.g., production separation vessels), the normal practice in the design of surface runoff is to provide a centerline slope from the process area (e.g., from a central pipe rack). This would also include... 

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