2008-009 (4) - Laserfiche WebLink

Home Browse Search

• Restore all surfaces, existing underground installations, etc. , damaged or cut as • a result of the excavations to their original conditions. 2. Trenches shall be made wide enough to allow a minimum of 2 inches between • parallel pipe lines. The minimum vertical clearance between lines crossing at angles greater than 45 degrees is 1 inch. Trenches for pipe lines shall be made of sufficient depth to provide the minimum cover from finish grade as follows: • a) 16 in. minimum cover over main lines. +` b) 16 in. minimum cover over control wires. • c) 12 in. minimum cover over lateral lines to heads . 3 . Where possible, install pipe adjacent to curbs or paving to minimize • interference with plants and their roots. Coordinate with landscape installer regarding proposed plant material locations. r 4. Keep trenches free of obstruction and debris that could tend to damage pipe and control wires. Remove excess soil from the site and leave grade as it was prior to sprinkler system installation. Piping shall be routed around shrubs, trees and other permanent obstacles. B . PIPE LINE ASSEMBLY • 1 . Install plastic pipe as recommended by the manufacturer and provide for expansion and contraction. Cut plastic pipe square. Remove burrs at cut ends +rr prior to installation so that a smooth unobstructed flow will be obtained. 2. Install remote control valves at locations no closer than 12 inches to walk +. edges, buildings and walls . Plastic pipe and fittings shall be solvent welded using solvents and methods as recommended by manufacturer of the pipe, except where screwed connections are required Pipe and fittings shall be • thoroughly cleaned of dirt, dust and moisture before applying solvent with a nonsynthetic bristle brush. Care should be taken not to use an excess amount of solvent, thereby causing a burr or obstruction to form on the inside of the • pipe. Allow the joints to set at least 24 hours before applying pressure on PVC pipe. Do not use PVC cement which has begun to gel. Do not attempt to _ make pipe connections during inclement weather conditions. C . SPRINKLER HEADS : Large gear-driven rotary type shall be installed so that the top is slightly above finish grade. If finish grade has not been established, set the top four inches above grade and lower when finish grade has been achieved. Sprinklers on risers shall be set at elevations so that there is no interruption of the • stream from the sprinkler nozzle caused by plant material during the first growing season ( 1 year from date of installation). Heads along curbs and walks shall be set flush to within 1 /8 inch and two to four inches away from curb or walk. Adjust • heads having an adjustment stem, for the proper radius and throw for the area involved. 2B-5 •