5,000 feet in long supply lines and 1,200 feet in main distribution loops or feeders. All branch mains connecting to feeder mains or feeder loops should have valves installed as close to the feeders as practical, so branch mains can be taken out of service without interrupting the supply to other locations. In the areas of greatest water demand or when the dependability of the distribution system is particularly important, maximum valve spacing of 500 feet may be appropriate. At intersections of distribution mains, the number of valves required is normally one less than the number of radiating mains; the valve omitted from the line is usually the one that principally supplies flow to the intersection. Valves are not usually installed on branches serving fire hydrants on military installations. As far as practical, shutoff valves should be installed in standardized locations (that is, the northeast corner of an intersection or a certain distance from the center line of a street), so they can easily be found in emergencies. For large shutoff valves (approximately 30 inches in diameter and larger), it may be necessary to surround the valve operator or entire valve with a vault to allow for repair or replacement. In important installations and for deep pipe cover, pipe entrance access manholes should be provided so valve internal parts can be serviced. When valves, vaults, or access manholes are not provided, all buried valves, regardless of size, should be installed with special valve boxes over the operating nut to permit operation from ground level by the insertion of a special long wrench into the box.
Proper clearance should be maintained between hydrants and poles, buildings, or other obstructions, so the hose lines can be readily attached and extended. Generally, hydrants are located at least 50 feet from a building and in no case are they located closer than 25 feet to a building, except where building walls are blank fire walls. Hydrants may be located adjacent to blank portions of substantial masonry walls where the chance of falling walls is remote.
Street intersections are the preferred location for fire hydrants because fire hoses can then be laid along any of the radiating streets. However, the likelihood of vehicular damage to hydrants is greatest at intersections, so the hydrants must be carefully located to reduce the possibility of damage. Hydrants should not be located less than 6 feet nor more than 7 feet from the edge of a paved roadway surface. When hydrants exceed this distance, consider stabilizing or surfacing a portion of the wide shoulders adjacent to the hydrants to permit connection of the hydrant and pumper with a single 10-foot length of suction hose. In some circumstances, it may not be practical to meet this criteria. Then try not to exceed 16 feet (two sectons of hose) to the pumper.
Hydrants should not be placed closer than 3 feet to any obstruction nor in front of any entranceway. The center of the lower outlet should not be less than 18 inches above the surrounding grade, and the operating nut should not be more than 4 feet above the surrounding grade.
In aircraft fueling, mass parking, servicing, and maintenance areas, the tops of hydrants must not be higher than 24 inches above the ground with the center of the lowest outlet not less than 18 inches above the ground. The pump nozzle should face the nearest roadway.
Here are rules for plumbing safety.
1. Keep the job clean.
2. Pick up scrap pieces of pipe.
3. Keep all tools and materials off the job when not in use.
4. Keep the shop floors dry and clean.
5. Keep the stockpiled materials carefully braced and blocked to prevent falling.
6. Lift with your legs, not your back.
7. Use pipe tongs for carrying heavy pipe sections.
8. Use proper tools for the job at hand.
9. Keep tools in good condition.
10. Use care in handling torches and hot lead.
11. Do not pour hot lead into a wet joint.
12. Use safety goggles, when required.
13. After installing fixtures, test the pipes for 1eaks and proper drainage before leaving the job
Q19. Hydrants should be located what distance from buildings?
Q20. The top of a hydrant must not be higher than how many inches above the ground?Continue Reading