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Pressure Zoning and Maintenance in the Los Angeles Distribution System
Author(s) -
Mamrelli Emil S.
Publication year - 1961
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1961.tb00796.x
Subject(s) - aqueduct , water level , pressure regulator , flow (mathematics) , environmental science , water flow , downstream (manufacturing) , zoning , volumetric flow rate , flow control (data) , engineering , hydrology (agriculture) , geotechnical engineering , environmental engineering , civil engineering , geography , mechanical engineering , mechanics , telecommunications , operations management , physics , cartography , archaeology
The growth and development of Los Angeles in the semi‐arid west has given rise to a water system with a large number of seasonal regulating reservoirs and one major aqueduct. The varied topography and allowable pressure range for water systems have required the establishment of over 100 pressure zones which are supplied by gravity water, regulated water, pumped water, or a combination of these sources. Several pressure zones are supplied by gravity water that is reduced in pressure at pressure‐reducing regulator stations as successively lower pressure zones are supplied. This article discusses a unique problem that was discovered in flow control stations using regulator‐type valves to control the flow of water, particularly in installations with low downstream pressures. The high velocities produced by throttled valves to control the rate of flow have resulted in a great deal of noise, vibration, and subsequent destruction of lining in the downstream enlarger as the water undergoes reduction in velocity. In an effort to eliminate the noise, vibration, and damage, very long enlargers were installed in the downstream portion of stations, but with no success. Flow control station designs using straight lengths of pipe connected directly to flat heads on large‐diameter pipe, without the use of reducers or enlargers, have been successful in eliminating the problem.