4338179.pdf

This is a record drawing document for mechanical and electrical systems in federal building facilities. The drawing provides detailed plans for Buildings 495, 496, and 497, specifically depicting basement and crawl space floor plans for new work installations.

The document shows piping and mechanical system layouts for water source heat pump installations, including 15-gallon expansion tanks, sump pump configurations, and related piping with various valve specifications and dimensions. The drawings indicate pipe sizes, connection points, and routing through the basement and crawl spaces. Electrical controls are depicted on the right side of the drawing, showing 120-volt relay systems for heat pump operation and unit disconnect switches. Purging notes specify that contractors must ensure the system is filled with water and properly vented before operation, with detailed procedures for opening and closing building valves during the initial startup sequence. The sequence of control section outlines that pumps serving Buildings 495 and 496 operate on a two-hour interval with thermostatic control for heat circulation. Scale notations indicate 1/2" = 1'-0" for most plan views and various cross-section scales. The document references internal and external duct liners and specifies materials such as polyethylene tubing for water line changes at connection points.