MECHANICAL SYSTEMS AND PLAN

To be able to prepare workable construction. drawings, EAs should have the ability to recognize and describe the materials used in mechanical systems, to understand their uses and functions, and to discuss the purpose and the development of a mechanical plan in the context of plumbing for water distribution and drainage systems. This chapter will discuss only the plumbing and drainage portions of the mechanical systems and the various materials used. You will not be expected to design the system; however, as an EA, you may be called upon to prepare construction drawings from sketches and specifications.

In general, plumbing refers to the system of pipes, fixtures, and other appurtenances used inside a building for supplying water and removing liquid and waterborne wastes. In practice, the term also includes storm water or roof drainage and exterior system components connecting to a source, such as a water main, and a point of disposal, such as a domestic septic tank or cesspool.

The purpose of plumbing systems is, basically, to bring a supply of safe water into a building for drinking, washing, and cooking, distribute the water within the building, and carry off the discharge of waste material from various receptacles on the premises to sewers, leech basins, and so forth, without causing a hazard to the health of the occupants. Codes, regulations, and trade practices define the plumbing specifications, which vary from one location or place of application to another. Although the National Plumbing Code is widely accepted as a guideline for the minimum requirements for plumbing designs, you must also be familiar with applicable local codes, especially when working with mechanical drawings and plans.

The purpose of a water distribution system is to carry potable COLD and HOT WATER throughout a building for domestic or industrial use. A typical water supply system (fig. 8-1) consists of service pipe, distribution pipe, connecting pipe, fittings, and control valves. The water service pipe begins at the WATER MAIN. The water distribution pipe starts at the end of the service pipe and supplies the water throughout the building.