Piping Systems cont'd

DOE-HDBK-1132-99

Piping systems that handle radioactive fluids require special design

considerations. Regardless of design pressures and temperatures, these

systems should be categorized as Normal Fluid Service, at a minimum, in

accordance with ASME B31.3 for design, material and component

selection, fabrication and erection, and examination and inspection.

Additional requirements should be added as determined necessary by

engineering design.

Maintenance activities that involve repairs, replacements, and

modifications to existing piping systems should be performed in

compliance with the original code of record used in the original design

and installation of these systems.

Process piping with surface temperatures exceeding 200 EF that

penetrates concrete walls, floors, and ceilings should be installed through

sleeves with insulation.

Piping and equipment with surface temperatures higher that 140 EF and

accessible from normal work areas, platforms, and access ways should

be insulated for personnel protection.

Excessive fluid velocities should be avoided in systems with condensed

liquids. Line losses rise dramatically with greater fluid velocities and the

potential to create undesirable vibrations increases.

Domestic water should be supplied by a separate service line. Combined

fire protection and potable water service or combined process water and

potable water systems should be avoided,

Backflow preventers and air gaps should be considered to prevent cross-

connection of potable water supplies. Vacuum breakers should be

considered to prevent back siphoning.

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