TABLE OF CONTENTS All water distribution systems are designed to keep the water flowing from the distribution system to the customer. However, when hydraulic conditions within the system deviate from the 'normal' conditions, water flow can be reversed. When this back flow happens, contaminated water can enter the distribution system. Back flow can be prevented by the installation of a device or assembly that uses valves, in different configurations, to prevent polluted or contaminated water from reversing direction and flowing backwards.
In the case of hotels or restaurants, the devices are used to prevent the property's water system from over pressurizing and forcing the water back into the municipality's system. In the United States and most other countries, laws and/or regulations require that water suppliers protect their water systems from contamination. In most cases, regulations exempt single-family residences used solely for residential purposes from assembly requirements. However, residences used for other purposes, including hotels, are required to install and maintain back flow prevention assemblies.
Generally the back flow prevention assembly is installed in the main water line to a building just after the water meter. Typically, annual or bi-annual testing of the assembly is required by the appropriate agency or fines can be incurred, including having the water turned off at the meter.
Stipanuk, D.M. (2002) Hospitality Facilities Management and Design, 2nd edn. Lansing, MI: Educational Institute of the American Hotel and Lodging Association.
Jim Ackles
Tharaldson Energy Group, USA
