Dry-Barrel Fire Hydrants AWWA Standard No. C502-73 |
Sec. 1. General. |
Hydrants shall be manufactured by the Mueller Company and shall be the Centurion fire hydrant-AWWA, which is the standard hydrant for the Township. |
A. | General Classification: |
| a.1. | Hydrants shall be dry barrel, post type with compression-type main valve closing with the pressure. |
| a.2. | Hydrants shall have a replaceable safety stem coupling and a replaceable safety flange at the ground line to prevent or minimize traffic damage. |
B. | Detail Specifications: |
| b.1. | Hydrants shall have a 4 1/2-inch main valve. |
| b.2. | The inlet connection shall be six-inch mechanical joint, dimensions shall comply with AWWA C111 and ANSI A21.11 Standards. |
| b.3. | Working pressure shall be 200 pounds per square inch and the pressure shall be 400 pounds per square inch. |
| b.4. | The dry top bonnet shall have a factory-lubricated bonnet assembly. |
| b.5. | The upper operating shall be bronze encased and have an O-ring stem seal. |
| b.6. | The nozzles shall be threaded and locked in place with a stainless steel screw. |
| b.7. | The safety stem coupling shall be below the lower barrel flange surface to prevent it being held open by vehicle wheel after traffic damage. |
| b.8. | Bronze seat ring shall thread into a bronze drain ring having two drain holes to provide an all-bronze drainway. |
| b.9. | The double drain valve shall operate automatically to force flush the drainway each time the hydrant is opened or closed. No toggles, springs or adjustable mechanism will be allowed. |
| b.10. | The main valve opening shall be controlled by a lug in the bottom of the shoe. |
| b.11. | The design of the shoe and upper valve plate shall permit maximum flow by reducing friction loss to a minimum. |
| b.12. | Nozzles: three-way, 2 1/2-inch nose nozzles and one pumper nozzle all with national standard hose threads. |
Certification of these specifications must be available to the Township. |
Sec. 7. Air Release and Surge Control. |
Air-release valves shall be located at high points along water supply pipelines to purge air pockets which may form at these high points. Air-release valves shall be installed in a valve vault and located below the frost line which is assumed to be four feet. Valves shall be ventilated and shall provide for drainage of water. |
At locations where a sudden change in water velocity may occur (booster stations, check valves, etc.) a pressure-release valve shall be provided to relieve the surge pressures. |
Sec. 8. Stream Crossings. |
Whenever water supply lines are to cross a stream or river below the bed, they shall be adequately sleeved and/or encased in no less than 1/2 foot of reinforced concrete within the reaches of the stream banks. Minimum depth of encasement below the stream banks shall be three feet. Water lines crossing streams on culverts or bridges shall be thoroughly insulated and protected with steel sleeves. |
Sec. 9. Wet Taps. |
All wet taps into existing water supply lines shall be made by a contractor approved by the Water Department. Tapping sleeves shall be cast-iron or ductile iron mechanical joint Mueller H615 or H616, depending on the outside diameter of the pipe being tapped. Sleeves shall have a minimum working pressure of 200 pounds per square inch. |
All sleeves and valves shall be set perfectly level along the center lines of the pipe tap. Valves, fittings and pipes shall conform to the applicable standards outlined herein. |
Sec. 10. Sanitary Protection. |
Chambers or pits containing valves or meters or other appurtenances shall be adequately drained. Drains shall not be connected directly to any storm sewer or sanitary sewer. |
Any air relief or vent pipes from chambers or beds must extend at least one foot above ground and be equipped with a down-facing elbow and insect screen. Physical connections other than the double-check valve assembly or reduced-pressure zone backflow preventer assembly are not permitted. |
While installing new water pipes, pipelines shall not be laid in water or where they can be flooded with water in the laying process. |
Underground drains from hydrants and valve chambers shall not be connected directly to sewers or storm sewers. |
In accordance with state regulations, water lines should be laid at an elevation above that of nearby sewers with joints no closer than that 10 feet from the sewer pipe center line. If this is not possible, water pipe shall be sleeved or encased in concrete with watertight tested joints. Where water lines cross sewer lines, water lines shall be laid above the sewer lines with vertical separation of not less than 18 inches. Hydrostatic pressure tests shall be performed to determine if there is any leakage. |
New water supply lines shall be disinfected by one of the procedures outlined herein before being placed into service. The absence of contamination shall be demonstrated by bacteriological examination before new lines and appurtenances are placed into service or accepted by the Water Department. This examination shall be certified by the Health Department. |
Sec. 11. Disinfection. |
Before new water lines are placed into service or accepted by the Water Department, they must be flushed and disinfected with chlorine solutions. During construction, precautions shall be taken to avoid unnecessary contamination. Disinfection is accomplished by one of the following methods. All are described in the American Water Works Association Standard on Water Main Disinfection, AWWA C601, latest revision: continuous feed method, slug method, tablet method. In all cases, disinfection procedures shall be performed in accordance with N.J.A.C. 7:10-11, Subchapter 11, Standards for Construction of Public Community Water Systems, Part 11.13 Disinfection. |
Sec. 12. Testing. |
Before water lines are placed into service or accepted by the Water Department, they shall be hydrostatically pressure tested. The test shall be witnessed by the Engineer. The pressure test shall be performed between valved sections of water lines and shall be submitted to a pressure of 150 pounds per square inch for a duration of four hours. |
Each valve section of pipe shall be slowly filled with water and the specified test pressure shall be applied by means of a pump connected to the pipe in a manner satisfactory to the Engineer. The pump, pipe connection, gauges, and all necessary apparatus shall be furnished by the developer. Before applying the specified test pressure all air shall be expelled from the pipe. If hydrants or air reliefs are not available at high places, the necessary taps shall be made at points of highest elevation before the test is made and the plugs inserted after the test has been completed. |
A leakage test shall be conducted after the pressure test has been satisfactorily completed. The duration of each leakage test shall be two hours, and during the test the main shall be subject to a pressure of 150 pounds per square inch and not permitted to fall below 145 pounds per square inch. |
Leakage is defined as the quantity of water to be supplied into the newly laid pipe, or any section thereof, necessary to maintain the specified leakage test pressure after the pipe has been filled with water and the air expelled. |
The maximum allowable leakage for the pipe shall be determined by the formula: |
| L = | NDP ___ 3,700 | |
in which L equals the allowable leakage in gallons per hour; N is the number of joints in the length of the pipeline tested; D is the nominal diameter of the pipe, in inches; and P is the average test pressure during the leakage test, in pounds per square inch. |