Operating units generated in pressurized irrigation systems have possibility of being operated on time and duration which is desired by the help of control units. As well as control units are used in garden-type small irrigation area having only one operation, the more developed ones can be done by means of a program which can operate several operations at the same time if requested. Electrical or wireless models of control units are used in areas in which electrise is problematic (Orta, 2009). If required, program used can regenerate irrigation program again by help of rain, wind and soil sensors placed in control units. Shut-down of system can be obtained by itself on the instant of rain through programming rain shutoff on control units. Also, it can prevent irrigation in case of soil’s having enough moisture by programming soil moisture sensors (Cardenas-Lailhacar et. al., 2008). Moisture sensors to be installed within working area provide more economic use of water, generating irrigation program.
Fig. 3. Control unit panel having 8 Station used in landscape irrigation Systems
4.1.3 Delivery line
Consist of pipes which deliver irrigation water from pump units to water emitters. A typical delivery line consists of main and lateral pipes and equipment which are used to tie those pipes. But submain and manifold are also included in great irrigation area.
220.127.116.11 Main line
They are pipes which transmit water from control units of water to submain canals if any, or to manifolds. Main canals carrying highest flow in system are manufactured as PVC and PE. Generally, 63-160 mm diameters are used depending on the size of system. They are the pipes in which frictional loss is at the most.