Landscape Irrigation
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 5
to Rev 6
in Landscape Irrigation.
---
title: Landscape Irrigation
…126 unchanged lines
- "Manufacturer warranties"
- "Spare-parts inventory turned over to Owner"
−default: [As-built irrigation record drawings, Controller programming record (as-left program), Field test reports (mainline pressure, lateral coverage, zone operation), Backflow assembly initial certification test report, Operation and maintenance (O&M) manuals, Laminated zone map mounted at controller, Manufacturer warranties, Spare-parts inventory turned over to Owner]
+default:
+ - "As-built irrigation record drawings"
+ - "Controller programming record (as-left program)"
+ - "Field test reports (mainline pressure, lateral coverage, zone operation)"
+ - "Backflow assembly initial certification test report"
+ - "Operation and maintenance (O&M) manuals"
+ - "Laminated zone map mounted at controller"
+ - "Manufacturer warranties"
+ - "Spare-parts inventory turned over to Owner"
```
…34 unchanged lines
### The water source determines the backflow protection required, the filtration required for drip and micro-irrigation, and, for reclaimed water, the marking and separation requirements imposed by the jurisdiction. {note}
+### The irrigation water source shall be as indicated on the drawings — potable supply, non-potable reclaimed/reuse supply, well, or surface water.
+
```datasheet
label: Irrigation Water Source
…9 unchanged lines
```
−### The irrigation water source shall be as indicated on the drawings — potable supply, non-potable reclaimed/reuse supply, well, or surface water.
−
### Where the source is reclaimed or reuse water, all piping, valve boxes, and appurtenances shall be identified in accordance with the jurisdiction's reclaimed-water requirements — typically purple (Pantone 522C) pipe or purple identification tape, purple valve box lids embossed with a non-potable warning, and the separation distances from potable lines required by the adopted plumbing code.
…30 unchanged lines
### For landscape irrigation a reduced-pressure-principle assembly is typical because it provides protection against both backsiphonage and backpressure and is accepted for high-hazard applications. {note}
+### A backflow prevention assembly shall be provided at the point of connection to protect the potable supply from the irrigation system, which the plumbing code classifies as a high-hazard cross-connection because of the potential for fertilizer, pesticide, and soil contaminants to be drawn back through the irrigation piping.
+
+### The assembly type shall be as required by the local cross-connection control program and as indicated on the drawings.
+
```datasheet
label: Backflow Prevention Assembly Type
…7 unchanged lines
```
−### A backflow prevention assembly shall be provided at the point of connection to protect the potable supply from the irrigation system, which the plumbing code classifies as a high-hazard cross-connection because of the potential for fertilizer, pesticide, and soil contaminants to be drawn back through the irrigation piping.
−
−### The assembly type shall be as required by the local cross-connection control program and as indicated on the drawings.
−
### The reduced-pressure-principle assembly is the recognized choice where any chemical injection (fertigation), where backpressure from elevated zones, or where high-hazard contaminants are possible. {note}
…6 unchanged lines
### Excess pressure mists spray nozzles into fine droplets that drift and evaporate, wastes water, and accelerates wear on every component; pressure regulation at the point of connection (in addition to, or in place of, pressure-regulating heads) is the most reliable way to control it. {note}
+### Where the static supply pressure exceeds the maximum operating pressure of the system components, a pressure-reducing valve or a master pressure regulator shall be provided downstream of the backflow assembly to limit the system pressure to the design value.
+
```datasheet
label: System Pressure Regulation at Point of Connection
…8 unchanged lines
```
−### Where the static supply pressure exceeds the maximum operating pressure of the system components, a pressure-reducing valve or a master pressure regulator shall be provided downstream of the backflow assembly to limit the system pressure to the design value.
−
# Piping Materials {toc}
…2 unchanged lines
### PVC pipe is the predominant material for buried commercial irrigation in most of the United States; polyethylene pipe is used where its flexibility, freeze tolerance, or suitability for trenchless pulling is advantageous, and is common in northern climates and on rocky sites. {note}
+### The pipe material for the mainline and laterals shall be as indicated on the drawings.
+
```datasheet
label: Mainline Piping Material
…19 unchanged lines
```
−### The pipe material for the mainline and laterals shall be as indicated on the drawings.
−
### The mainline operates under continuous (constant) pressure between the point of connection and the zone valves, and therefore warrants the more conservative material — Schedule 40 PVC or a heavier pressure class — and gasketed joints on larger diameters to accommodate thermal movement. {note}
…59 unchanged lines
### PE is well suited to freeze-prone climates because it expands rather than splitting under residual ice, and to rocky or trenchless conditions because it can be pulled through a bored path. {note}
+### Polyethylene pipe, where indicated, shall conform to ASTM D2239 (controlled inside diameter) or ASTM D3035 (controlled outside diameter), manufactured from a PE compound conforming to ASTM D3350.
+
+### PE pipe shall be joined with the manufacturer's barbed insert fittings secured with stainless steel pinch clamps or screw clamps, or by thermal fusion where indicated for larger diameters.
+
```datasheet
label: Polyethylene Pipe Joining
…6 unchanged lines
```
−### Polyethylene pipe, where indicated, shall conform to ASTM D2239 (controlled inside diameter) or ASTM D3035 (controlled outside diameter), manufactured from a PE compound conforming to ASTM D3350.
−
−### PE pipe shall be joined with the manufacturer's barbed insert fittings secured with stainless steel pinch clamps or screw clamps, or by thermal fusion where indicated for larger diameters.
−
# Valves and Valve Boxes {toc}
…139 unchanged lines
### This overlap is required because the application depth from a single sprinkler is heaviest near the head and tapers to nearly nothing at the edge of its throw; without overlap, the areas between heads receive far less water than the areas near them, producing the characteristic ring or doughnut dry pattern. {note}
+### Spray heads and rotors shall be installed at the spacing indicated on the drawings to achieve head-to-head coverage — each head's throw reaches the adjacent heads, so that every point in the zone receives water from at least two heads.
+
```datasheet
label: Head Spacing Basis
…6 unchanged lines
```
−### Spray heads and rotors shall be installed at the spacing indicated on the drawings to achieve head-to-head coverage — each head's throw reaches the adjacent heads, so that every point in the zone receives water from at least two heads.
−
### The Contractor shall install heads at the design spacing and shall not increase spacing to economize on heads, because head spacing greater than the head-to-head design destroys distribution uniformity.
…10 unchanged lines
# Drip and Micro-Irrigation {toc}
−## Application {toc}
+## Drip and micro-irrigation shall be used for planting beds, shrub masses, groundcover, individual trees, and other non-turf areas as indicated, and for turf only where subsurface drip is specifically designed for the area.
−### Drip and micro-irrigation shall be used for planting beds, shrub masses, groundcover, individual trees, and other non-turf areas as indicated, and for turf only where subsurface drip is specifically designed for the area.
+## Drip irrigation applies water slowly and directly to the root zone, achieving very high application efficiency and eliminating the wind drift and evaporation losses of spray irrigation; it is the preferred method for beds and is frequently required by water-efficient landscape ordinances for all non-turf plantings. {note}
−### Drip irrigation applies water slowly and directly to the root zone, achieving very high application efficiency and eliminating the wind drift and evaporation losses of spray irrigation; it is the preferred method for beds and is frequently required by water-efficient landscape ordinances for all non-turf plantings. {note}
−
## Drip Zone Control Assembly {toc}
### The filter protects the small emitter passages from clogging and the pressure regulator holds the drip line at the low pressure (commonly 15 to 40 psi) at which the emitters are rated; both are essential, and a drip zone fed at an unregulated, unfiltered pressure will clog and blow apart. {note}
+### Each drip zone shall be served by a zone control assembly consisting of, in order, the remote control valve, a line-size filter, and a pressure regulator, sized for the zone flow and set to the design operating pressure of the drip product.
+
```datasheet
label: Drip Zone Filtration
…19 unchanged lines
```
−### Each drip zone shall be served by a zone control assembly consisting of, in order, the remote control valve, a line-size filter, and a pressure regulator, sized for the zone flow and set to the design operating pressure of the drip product.
−
## Emitters and Dripline {toc}
### Emitter flow rate and spacing are selected for the plant water demand and the soil's lateral wetting characteristics. {note}
+### Drip devices shall be pressure-compensating so that every emitter delivers the same flow regardless of its position along the line or its elevation, which is what allows long runs and sloped beds to water uniformly.
+
+### Inline-emitter dripline (tubing with emitters factory-installed at a fixed spacing) shall be used for bed and groundcover coverage.
+
+### Point-source emitters on distribution tubing shall be used at individual trees and specimen plants as indicated.
+
+### Emitter flow rate and spacing shall be as indicated on the drawings, selected for the plant water demand and the soil's lateral wetting characteristics.
+
```datasheet
label: Dripline Emitter Flow Rate
…20 unchanged lines
```
−### Drip devices shall be pressure-compensating so that every emitter delivers the same flow regardless of its position along the line or its elevation, which is what allows long runs and sloped beds to water uniformly.
−
−### Inline-emitter dripline (tubing with emitters factory-installed at a fixed spacing) shall be used for bed and groundcover coverage.
−
−### Point-source emitters on distribution tubing shall be used at individual trees and specimen plants as indicated.
−
−### Emitter flow rate and spacing shall be as indicated on the drawings, selected for the plant water demand and the soil's lateral wetting characteristics.
−
## Air/Vacuum Relief and Flushing {toc}
### The air/vacuum relief valve admits air when the zone shuts down so that the emptying line does not develop a vacuum and draw soil and debris back into the emitters; the flush point allows accumulated sediment to be flushed from the line. {note}
### Without these, dripline progressively clogs from the ends inward and from soil ingestion at shutdown. {note}
+### Each drip zone shall include an air/vacuum relief valve at the high point of the zone and a flush point (flush valve or flush cap) at the end of each dripline run or at a manifolded flush header.
+
```datasheet
label: Drip Zone Air/Vacuum Relief and Flush
…6 unchanged lines
```
−### Each drip zone shall include an air/vacuum relief valve at the high point of the zone and a flush point (flush valve or flush cap) at the end of each dripline run or at a manifolded flush header.
−
## Subsurface Drip {toc}
…74 unchanged lines
### The master valve protects the site against the continuous risk of a mainline leak or a stuck-open zone valve dumping water for hours or days while the system is unattended; combined with the flow sensor it is the basis of automatic leak detection. {note}
+### A normally-closed master valve shall be installed on the mainline immediately downstream of the backflow assembly (or as indicated) and wired to the controller so that the mainline downstream of the master valve is pressurized only when a zone is calling for water.
+
```datasheet
label: Master Valve
…6 unchanged lines
```
−### A normally-closed master valve shall be installed on the mainline immediately downstream of the backflow assembly (or as indicated) and wired to the controller so that the mainline downstream of the master valve is pressurized only when a zone is calling for water.
−
## Flow Sensor {toc}
### The flow sensor lets the controller learn the expected flow of each zone and detect abnormal flow — a broken lateral or a sheared head shows up as flow higher than the zone's expected value, and a clogged zone or a stuck-closed valve shows up as flow lower than expected. {note}
### On detecting an abnormal flow, the controller can shut the master valve and alarm, limiting the loss to a single cycle rather than days of leakage. {note}
+### A flow sensor shall be installed on the mainline downstream of the master valve and wired to the controller where the controller supports flow monitoring.
+
```datasheet
label: Flow Sensor and High-Flow Shutdown
…7 unchanged lines
```
−### A flow sensor shall be installed on the mainline downstream of the master valve and wired to the controller where the controller supports flow monitoring.
−
## Rain and Freeze Sensors {toc}
…51 unchanged lines
### The sleeve allows the pipe or wire to be installed, repaired, or replaced without cutting the pavement, and protects the pipe from the load and the saw-cutting that pavement work involves. {note}
+### Pipe and control wire crossing under paving, sidewalks, curbs, or other hardscape shall be installed in sleeves placed before the paving is constructed.
+
+### Sleeves shall be Schedule 40 PVC (or other approved conduit) sized at not less than twice the diameter of the pipe or bundle they carry, extend not less than 12 inches beyond the edge of paving on each side, and be marked at each end so they can be located after paving.
+
```datasheet
label: Sleeve Material and Sizing
…6 unchanged lines
```
−### Pipe and control wire crossing under paving, sidewalks, curbs, or other hardscape shall be installed in sleeves placed before the paving is constructed.
−
−### Sleeves shall be Schedule 40 PVC (or other approved conduit) sized at not less than twice the diameter of the pipe or bundle they carry, extend not less than 12 inches beyond the edge of paving on each side, and be marked at each end so they can be located after paving.
−
### Pipe sleeves and wire sleeves shall be separate; control wire shall not share a sleeve with a pressure pipe, so that a pipe repair does not require disturbing the wire and vice versa.
…129 unchanged lines
### Excessive air pressure ruptures fittings and over-speeds rotor gears. {note}
+### In freeze-prone climates the system shall be winterized at the end of each watering season by isolating the supply, draining the backflow assembly and exposed components, and clearing water from the buried piping either by gravity drainage to drain valves at low points or by compressed-air blow-out.
+
```datasheet
label: Winterization Method
…8 unchanged lines
```
−### In freeze-prone climates the system shall be winterized at the end of each watering season by isolating the supply, draining the backflow assembly and exposed components, and clearing water from the buried piping either by gravity drainage to drain valves at low points or by compressed-air blow-out.
−
### Where the winterization method is compressed-air blow-out, the air supply shall be regulated so that the blow-out pressure does not exceed the lowest-rated component on the zone being cleared, and in no case exceeds 80 psi for PVC piping or 50 psi for polyethylene piping.
…48 unchanged lines
### The inventory shall include a representative quantity of each type of nozzle installed, spare drip emitters and fittings, the special tools required to service the heads and valves installed (including the quick-coupler key and the controller key), and spare waterproof wire-splice connectors.