The plumbing system in a typical home is a complex network of water supply pipes, drain pipes, ventilation pipes, and more. It's often referred to as a DWV (drain-drain) system and is the least visible part of the house's entire plumbing system. To ensure that the plumbing system is up to code, some state and local plumbing codes prohibit the use of certain materials in water distribution systems. By planning ahead, you can often reduce your total plumbing expenses by locating bathrooms, kitchens, or laundry rooms close to each other so that they can share parts of the system.
This article covers the main characteristics of a residential plumbing system and the basic plumbing terms and principles that an inspector must know and understand to identify housing code violations related to plumbing. Having a basic understanding of the three types of plumbing systems in your home will help you understand if your plumber is taking care of (or taking advantage of you). To understand the proper maintenance procedures to prevent and eliminate water quality problems in plumbing systems, it is necessary to understand the process used to determine the chemical aggressiveness of water. Plumbing does not include drilling water wells, installing equipment to soften water, or manufacturing or selling plumbing accessories, appliances, equipment, or hardware.
Because a piping system is subject to large variations in flow, and this flow originates from many different sections of the system, pressures vary widely in the drain lines. The seal of a plumbing trap can be lost due to the siphon (direct and indirect or by impulse), backpressure, evaporation ratio, capillary attraction or the effect of the wind. The part of the pipe ventilation system that is generally least known to most homeowners is connected to the drain pipes and its function is to vent sewage gases so that they do not accumulate in the house. A piping system is ventilated to prevent loss of the trap seal, material deterioration and flow delay.
Without ventilation, the traps in the pipes would work the same way as if you were to cover the straw with your finger. A plumbing trap is a device that is used in a waste system to prevent the passage of sewer gas to the structure and yet not to greatly hinder the discharge of the device. Many codes require a gate valve on the inner side of the meter to shut off the water supply for plumbing repairs.