water which is safe for human consumption; any harmful bacteria has been killed by either chlorination or ultraviolet treatment
public water main;
the public (city, village or municipality) water supply system; the public employee responsible for this system is called the water purveyor
a shut off valve attached to the public water main; this valve is installed by city or municipal works crews
a quarter turn plug cock installed at the property line; you activate a curb cock with a long T handle wrench
water service pipe
this pipe conveys water from the public water main or private water source to the inside of the building
water service stop or shut off valve
a shut off valve installed immediatleyly inside the building on the water service pipe
pressure reducing valve
a valve which reduces higher city pressures to the acceptable safe working limits of valves and appliances installed in the building
a measuring device used to record water usage by a customer; it could be installed in a meter box at the property line or inside on the water service in a commercial building
water distibution system
this is the term applied to the total water pipe system from the water service stop (shut off valve) to all staops, valves, appliances and fixtures
a water distribution pipe that extends through at least one full storey
water pipe branch
a pipe that supplies water from a main to a fixture or outlet, or an arrangement of pipe that supplies water to fixtures or outlets, with a maximum distance of seven meters to the furthest fixture or outlet
water pipe main
the principalartery to which the branches are connected
service water heater
a system for heating water for a water distribution system; these systems include electric oil or gas fired hot water tanks, which have their own limited storage capacity, indirect water heaters, which require a boiler for the heating source, and tankless gas fired water heaters which give continuous hot water on demand
temperature and pressure releif valves
these valves are designed to relieve excessive temperatures and pressures that may be created in service water heaters; these devices must be installed on all service water heaters; the only rare exceptions are equipment manufacturers who have had their equipment exempted
vacuuum relief valve
this valve must be installed on every service water heater to protect the water heater fro collapsin, due to siphonic action that may be created if a city water main ruptures and there is a flow reversal of potable water; a vacuum releif valve is also needed to protect an electric service water heater, so that if the heater suddenly loses its water, the heating elements will not burn out
shut off valves
every water service pipe, water closet and service water heater shall be equippped with a shutoff valve
every hose bib located on the exterior of a building shall be equipped with either a stop and waste valve on the inside of the building or a frost proof hydrant which will then replace the hose bib; these allow for drainage to prevent frozen pipes and fittings
shower valves or bathtub valves with shower diverter
these valves are installed at the same time as the water pipe rough in occurs; the diverter fitting does what the name implies, that is, it diverts water to the tu spout or to the shower heat, depending on which way the lever is turned
cross connection control devices
these devices are designed to prevent back siphonage and back pressure of non potable water into the potable water system; cross connection control devices are generally used on commercial or industrial buildings
support used by plumbers to hold pipes, fittings, shower and bathtub valves, fixtures, etc; backing must be strong enough to support the fixture, pipe, ect. with out movement or sagging; this material is usually 2x4, 2x6, 2x8
a cross connection is any physical arrangement where a city or municipal water supply is connected, directly or indirectly, with any non potable or unapproved water systom which may containt harmful substances
back flow is the reverse flow of water or other liquids from any source into the potable water supply within a facility and/ or city or municipal water supply.
is caused by negative presure or a reduced pressure in the supply piping.
may cause backflow to occure when the potable supply piping is conected to a system or fixture which exceeds the operating pressure of the potable supply piping.
approved air gap separation
an approved air gap is a physical separation between the free flowing discharge end of a potable water supply pipeline and the overflow rim of an open or non-pressure reciving vessel.
to deprive (something) of value or effectiveness; make futile or of no consequence.
used to protect the potable water system from extreme hazards which may be injurious to health. Best protection against backflow
Double check valve assembly (DCVA)
an effective device to prevent backflow caused by back pressure and back-siphonage and is used to protect the water system from substances which are not hazardous to health
detector double check valve assembly (DDC)
used to detect leakage or theft. its a hybrid version of a mainline DCVA with the addition of a smaller, factory-installed DCVA and a meter in a bypass configuration
pressure vacuum breaker (PVB)
pressure vacuum breakers are designed to only prevent back siphonage and cannot be used in an area where positive pressure can be developed on the downstream side of the device or in an area where the vacuum breakers are subject to flooding
Atmospheric vacuum breaker (AVB)
designed to only prevent back siphonage. its a device which allows air to enter the waterline when the line pressure is reduced to a guage pressure of zero or below.