The micro-irrigation system has lower pressure requirements, soil is cheaper to operate. Pressure compensating devices a teach outlet should only be specified on hilly land where laterals cannot be positioned on the contour. be positioned on the contour. Pipe sizing Economical pipe sizes often have a friction loss ranging from 0.4m to 1.2 metres per 100 metres of pipe. The most economical pipe size will vary with the pipe longevity, hours of pumping, interstate, pipe friction, energy cost and the current cost of pipe. Water flow in pipes should be laminar.
Turbulent flows have high friction losses and reduce the pipes' operating life.
Saving money by purchasing smaller diameter pipes may lead to problems in efficiency and increased operating expenses. The use of air release valves at high points should be considered. The mainline should be a minimum of Class 9 or one class higher than that specified for the operating pressure. This will cater for the extra pressure caused by water hammer. Pipe strength decreases as temperatures increase.