Landscape and Irrigation is read by decision makers throughout the landscape and irrigation markets — including contractors, landscape architects, professional grounds managers, and irrigation and water mgmt companies and reaches the entire spetrum.
Issue link: http://read.dmtmag.com/i/652278
www.landscapeirrigation.com Landscape and Irrigation April 2016 17 above ground and below ground are potentially hazardous. Above-ground risks may be due to adverse weather conditions of electrical storms, wind storms and flooding. Below-ground conditions, including dampness, result in corrosion of connectors, flooded communication components, soil-borne pests/vermin, root intrusion and rocks. Below ground is also subject to electrical damage from lightning, especially decoder systems. People are also a risk, with interference to the operation of systems and in some cases deliberate vandalism. Water quality is becoming an increasing risk. As the level of use of lower-quality water increases, so does the potential for malfunction of components. There are also potential health risks to people and the environment. COMMON FAULTS Some parts of an irrigation system are likely to require more maintenance than others due to the function and complexity of the equipment or device, the operating environment and the number of units in use. Some examples of items that are prone to higher levels of maintenance include: Rotors/sprinkler heads Multiple units — e.g. 50 to 80 heads on a sports ground Stream trajectory sensitive to nozzle size, nozzle condition, hydraulic operating conditions Water distribution sensitive to installed position; depth and vertical alignment Soil environment — sand/debris may interfere with rotation and distribution or wear seals External loads and stresses — reduce effectiveness Solenoid valves Diaphragm operation sensitive to internal port blockage (water quality) Low voltage supply/power (24 V AC) is vulnerable to small voltage drops Electrical connections in harsh soil environment Function dependent on two subsystems of electrical and hydraulic Numerous units in the field Drip emitters Multiple units — hundreds/thousands Small pathways — blockage External loads and stresses — tubing interfered with or damaged Dripline tubing connections vulnerable PREVENTATIVE MAINTENANCE PROGRAMS The overall objective should be to have in place a sound preventative maintenance program that reduces the need for unscheduled service during the irrigation season. A preventative maintenance program should include the mechanical and electrical components, as well as the hydraulic and water application performance of the system. The main items to be included are: Pump — Electrical power consumption and condition; mechanical, e.g. bearings; hydraulic e.g. flow and pressure Filter — Debris; flushing; flow, pressure loss Controller — Programs suited to site; voltage output, earth protection systems Wiring — Resistance of circuits, including connectors; evidence of deterioration Sensors — Operation and controller response; sensor calibration Pressure regulation — Settings; pressure check Flow monitoring — Output signal; display and recording Valves — Operation; Opening and closing Piping and joins — Leakage Sprinklers — All heads operation; condition and delivery performance Drip emitters — Delivery rate; blockage; application position Drip tubing — Connections; wetting pattern Repair saddle failure due to corroded bolts in aggressive soil. Specifying the right materials reduces the need for reactive maintenance. IRRIGATION AND WATER MANAGEMENT