Irrigation Answers
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1. Answer the following questions using Canadian Landscape Standards for Irrigation
- supplied hard copy
Whose job is it to make sure the sequencing of the irrigation install is carried out in coordination with other trades?
- Irrigation contractor
What are the requirements for water used for irrigation purposes? Confirm the irrigation design plan accounts for local water laws or regulations, permitting requirements and applicable codes.
Water must comply with local/provincial water-quality guidelines
What type of backfill should be used around an irrigation pipe? Backfill shall not have rocks or debris greater than ½ ‐ inch in size next to the pipe. Standards for landscape irrigation systems? Landscape irrigation standards make sure systems are efficient, durable, and save water.
They focus on even water coverage, using smart and low-water components, setting the right pressure, installing pipes correctly, preventing backflow, and winterizing.
Regular maintenance and inspections are also important.
Workmanship and materials should be guaranteed for how long? 1 year List 3 things that should be provided or submitted to the client? 1. Scaled built drawing showing all components and locations (controller, valves, main, blow out, etc.).
- Operating & maintenance manual (zone map, run times, seasonal start/stop, winterizing).
- Written warranty/guarantee covering workmanship & materials (minimum 1 year).
Design Maximum spacing for sprinklers? Maximum spacing = head to head coverage (equal to the sprinkler’s radius of throw)
Space sprinklers a minimum of 2 inches from hard surface edges but farther than
2 inches where possible to minimize overspray, back
‐ splash or wind drift.
2. How do you determine riser height? Choose riser height based on plant material
growth, obstructions and maintenance access so the head achieves good coverage as plants mature.
What must be used for low head drainage? Check Valves to Control Low head drainage
- What type of sprinkler
( accessories) should be used on sports fields? rubber covers
What is the maximum velocity of flow in an irrigation system? Velocity shall not exceed
5 feet per second for pipes 3 ‐ inch diameter or smaller.
What is the maximum pressure variation within each zone? Pressure variation within a zone shall have less than
- 10 percent variation
What types of sensors are recommended? Wireless sensors (rain, soil moisture, flow, etc.) shall follow manufacturer’s recommendations for proper operation and installation.
When can you put an indoor controller outdoors? Settings to be used if a smart controller is installed 1) For weather-based controllers Soil type and slope Plant factors Precipitation or application rates
- For soil-moisture-based controllers Settings for the soil moisture sensor to initiate or suspend irrigation
What is trace wire used for? Trace wire is a single insulated wire buried next to plastic pipes so workers can find them later for repairs or maintenance.
When would you use a butterfly valve over a ball or gate valve? Use a butterfly valve for large pipes with low to medium pressure. Use ball or gate valves for small pipes or when a tight shut-off is needed.
What colour is the common wire in a controller? white
What is the smallest size wire that should be used for irrigation?
- 18 gauge
What class/ Series PVC pipe should you use for a ¾ “ pipe? 200 What material and size should be used as sleeving material? Sleeving should be twice the size of the piping or wiring bundle that it will hold
(2 ‐ inch pipe in a 4 ‐ inch sleeve and wires that fit in a
1 ‐ inch conduit shall have a 2 ‐ inch sleeve).
3. How much backfill is required over the pipe in a residential lawn...
How much backfill is required over the pipe in a residential lawn area? 8-12 inches How far should you dig your trench from a paving stone walkway? 12 inch? 18-24? If possible where should the valve box be located? Place valve boxes where they are safe, look good, and will last long.
- Don’t put them in sports fields or recreation areas.
- Keep them out of walkways and paths.
- Use purple valve boxes if reclaimed water is used.
What is the minimum valve box size for 2 - 1” valves? 12-18 inch? What assembly is connected between a pop-up sprinkler and the pipe? Riser or swing joint assembly Where is wire installed in an irrigation system? Underground in trenches What are the specifications for a water pipe running under a driveway that cannot be installed in a sleeve?
If a water pipe runs under a driveway without a sleeve, it must be made of strong, flexible material that can handle pressure and ground movement.
What is the purpose of testing an irrigation system after install?
Testing makes sure
- There are no leaks and pipes are in good condition.
- Each zone and valve work properly with correct pressure and coverage.
- The controller and sensors work, and the system is set up and ready for winter if needed.
4. What information should be included on a typical as-built drawing plan?
An as-built drawing should show all parts that were installed, their exact locations, measurements from fixed points, zone map, and any changes made from the original design.