Results
#1. What is the required protection for potable water make-up connections to steam or hot water boilers?
#2. What is the minimum number of walls required for heat exchangers or assemblies using potable water?
#3. What is the alternative backflow preventer that can be installed for lawn sprinkling systems if atmospheric vacuum breakers cannot be installed?
#4. What is the purpose of Section 603.1 of the plumbing code?
#5. What equipment shall be protected by a listed backflow preventer installed in accordance with the requirements of this Chapter?
#6. What is required to protect water closet flushometer tanks against backflow, according to Section 603.4.3?
#7. What is the purpose of Section 602 of the plumbing code?
#8. What type of backflow prevention assembly is required for hot water over 43.3°C, according to Section 603.3.5?
#9. What is the purpose of Section 602.3 of the plumbing code?
#10. How much clearance must be provided for testing, maintenance, and repair of a backflow prevention assembly, according to Section 603.3.3?
#11. What is the critical level required for atmospheric vacuum breakers installed on inlets to tanks, vats, sumps, swimming pools, and other receptors?
#12. Which section in the code requires heat exchangers and other constructions using potable water to be made of listed construction and materials?
#13. What is the required location for an atmospheric vacuum breaker to protect potable water outlets with hose attachments?
#14. What is the purpose of an airgap in plumbing systems?
#15. What is the minimum airgap required to provide backflow protection according to Table 6-1 in Section 603.2.1 of the plumbing code?
#16. What is the required protection for water inlets to water-supplied aspirators?
#17. According to Section 603.3.1, what must backflow prevention assemblies conform to?
#18. What type of backflow prevention is required for water closet and urinal flushometer valves, according to Section 603.4.1?
#19. What is the purpose of Section 602.2 of the plumbing code?
#20. What is the purpose of Section 603 of the plumbing code?
#21. What shall be considered a non-potable water line in cases where it is impractical to correct individual cross-connections in the domestic water line?
#22. What is the purpose of Section 601 of the plumbing code?
#23. According to Section 603.3.4, what is the minimum approved air gap required for potable water discharge to the drainage system?
#24. What is the purpose of Section 602.1 of the plumbing code?
#25. According to Section 603.3.6, how should fixtures, appliances, or appurtenances with integral backflow preventers or integral air gaps be installed?
#26. Backflow preventers shall not be installed in any area containing fumes that are:
#27. What is an Atmospheric Vacuum Breaker (AVB)?
#28. What shall be posted on each outlet on the non-potable water line that may be used for drinking or domestic purposes?
#29. What is the purpose of the approval process for backflow prevention devices or assemblies in the plumbing code?
#30. When must a backflow prevention assembly be tested, according to Section 603.3.2?
Chapter 6: WATER SUPPLY AND DISTRIBUTION (Part 1)
Section 601 – RUNNING WATER REQUIRED
Each plumbing fixture shall be provided with an adequate supply of potable running water arranged to flush and keep it in a clean and healthful condition without any danger of backflow or cross-connection. Water closets and urinals shall be flushed by means of an approved flush tank or flushometer valve. Faucets and showers shall be connected to the hot and cold water distribution supplies, so that the hot water supply is located on the left side of the combination fitting.
Section 602 – UNLAWFUL CONNECTIONS
602.1 No installation of potable water supply piping or any part thereof shall be made in such a manner that it will be possible for used, unclean, polluted, or contaminated water, mixtures, or substances to enter any portion of such piping system from any receptacle, equipment, or fixture by reason of back-siphonage, suction, or any other cause, either during normal use and operation thereof or when any such tank, receptacle, equipment, or plumbing fixture is flooded, or subject to pressure in excess of the operating pressure in the hot or cold water pipings.
602.2 No person shall make a connection or allow one to exist between pipes or conduits carrying domestic water supplied by any public or private water service system and any pipe, conduit, or fixture containing or carrying water from any other source or containing or carrying water that has been used for other purposes or any piping carrying chemicals, liquids, gases, or any substances unless there is provided an approved backflow prevention device.
602.3 No plumbing fixture, device, or construction shall be installed, maintained, or connected to any domestic water supply when such installation or connection may provide a possibility of polluting such water supply or may provide a cross-connection between potable water distributing system and water which becomes contaminated by such plumbing fixture, device, or construction unless there is provided an indirect connection or a backflow prevention device.
Section 603 – CROSS-CONNECTION CONTROL
603.1 Cross-connection control shall be provided in accordance with the provisions of this chapter. No person shall install any water-operated equipment or mechanism or use any water treating chemical or substances if it is found that such equipment, mechanism, chemical, or substance may cause pollution or contamination of the domestic water supply. Such equipment or mechanism may be permitted only when equipped with an approved backflow prevention device assembly.
Approval of Devices or Assemblies – Before any device or assembly is installed for the prevention of backflow, the Administrative Authority shall have first approved it. Devices or assemblies shall be tested for conformity with recognized standards or other standards acceptable to the Administrative Authority, which are consistent with the intent of this code.
The person or persons having control of such devices or assemblies shall maintain all devices or assemblies installed in a potable water supply system for protection against backflow in good working condition. The Administrative Authority or other department having jurisdiction may inspect such devices or assemblies and, if found to be defective or inoperative, shall require the repair or replacement thereof. No device or assembly shall be removed from use or relocated, or other device or assembly substituted, without the approval of the Administrative Authority.
No water piping supplied by any private water supply system shall be interconnected to an approved city water supply system or any other source of supply without the approval of the Administrative Authority, Health Department, or other agencies.
603.2 Water Supply and Backflow Prevention Devices and Methods
603.2.1 Airgap – The minimum airgap to provide backflow protection shall be in accordance with Table 6-1.
603.2.2 Atmospheric Vacuum Breaker (AVB) – Consists of a body, a checking member, and an atmospheric opening.
603.2.3 Double Check Valve Backflow Prevention Assembly (DC) – Consists of two independently acting internally or externally loaded check valves, four properly located test cocks with connectors, and two isolation gate valves.
603.2.4 Pressure Vacuum Breaker Backflow Prevention Assembly (PVB) – Consists of a loaded air inlet valve, an internally loaded check valve, two properly located test cocks, and two isolation gate valves.
603.2.5 Reduced Pressure Principle Backflow Prevention Assembly (RP) – Consists of two independently acting internally loaded check valves, a differential pressure relief valve, four properly located test cocks, and two isolation gate valves.
TABLE 6-1
MINIMUM AIRGAPS FOR WATER DISTRIBUTION
| Item No. | Fixtures (1) | When not affected by the side walls mm (2) | When affected by the side walls mm (2) |
| 1. | Lavatories and other fixtures with effective openings not greater than 13mm in diameter | 25 | 38 |
| 2. | Sinks, laundry trays, gooseneck bath faucets and other fixtures with effective openings not greater than 19 mm in diameter | 38 | 57 |
| 3. | Over rim bath fillers and other fixtures with effective openings not greater than 25 mm in diameter | 51 | 76 |
| 4. | effective openings not greater than 25 mm in diameter | two(2) times diameter of effective opening | Three(3) times diameter of effective openig |
| 1.Side walls, ribs, or similar obstructions do not affect air gaps when spaced from the inside edge of the spout opening a distance greater than three times the diameter of the effective opening for a single penetration or a distance greater than four times the effective opening for a single wall, or a distance greater than four times the effective opening for two intersecting walls. 2.Vertical walls, ribs, or similar obstructions extending from the water surface to or above the horizontal plane of the spout opening, other than specified in Note 1 above. The effect of three or more such vertical walls or ribs has not been determined. In such cases, the air gap shall be measured from the top of the wall. 3.The effective opening shall be the minimum cross-sectional area at the seat of the control valve of the supply pipe or tubing that feeds the device or outlet. If two or more lines supply one outlet, the effective opening shall be the sum of the cross-sectional areas of the individual supply lines or the area of the single outlet, whichever is smaller. 4.Air gaps less than 25 mm shall only be approved as a permanent part of a listed assembly that has been tested under actual backflow conditions with vacuums of from 0 to 63.5 cm of mercury. |
TABLE 6-2
BACKFLOWS ASSEMBLIES, DEVICE AND METHODS
| 1. See the description of devices and assemblies in this chapter. 2. Installation in a pit or vault requires previous approval from the Administrative Authority. 3. Refer to the general and specific requirements for installation. 4. It should not be subjected to operating pressure for more than 12 hours in any 24-hour period. |
603.3 General Requirements
603.3.1 All assemblies shall conform to listed standards and be acceptable to the authority having jurisdiction over the selection and installation of backflow prevention assemblies.
603.3.2 The premises owner or responsible person shall have the backflow prevention assembly tested by a certified backflow assembly tester at the time of installation, repair, relocation, and at least on an annual schedule or more often when required by the administrative authority.
603.3.3 Access and clearance shall be provided for the required testing, maintenance, and repair. Access and clearance shall require a minimum of 305mm space between the lowest portion of the assembly and the grade, floor, or platform. Installations elevated more than 1.52 meters above the floor or grade shall be provided with a permanent platform capable of supporting a tester or maintenance person.
603.3.4 Direct connections between potable water pipings and sewer-connected wastes shall not exist under any condition with or without backflow protection. Where potable water is discharged to the drainage system, it shall be by means of an approved air gap of two (2) pipe diameters from the supply outlet and the top surface of the drainage inlet, but in no case shall the gap be less than 25 mm. Connection may be made to the inlet side of a trap provided that an approved atmospheric vacuum breaker is installed less than 152mm above the flood level rim of such a trapped fixture so that at no time will any such device be subjected to any back-pressure.
603.3.5 Backflow prevention for hot water over 43.3°C shall be a listed type assembly designed to operate at a temperature of 43.3°C or higher without rendering any portion of the assembly inoperative.
603.3.6 Fixtures, appliances, or appurtenances with integral backflow preventers or integral air gaps manufactured as a unit shall be installed in accordance with their listed requirements.
Water Supply and Distribution
603.4 Specific Requirements
603.4.1 Water Closet and Urinal Flushometer Valves shall be equipped with a listed atmospheric vacuum breaker. The vacuum breaker shall be installed at the discharge side of the flushometer valve with the critical level at least 152mm or the distance according to its listing above the overflow rim of a water closet bowl or the highest part of a urinal.
603.4.2 Water Closet and Urinal Tanks shall be equipped with a listed ballcock. The ballcock shall be installed with the critical level at least 25mm above the full opening of the overflow pipe. In cases where the ballcock has no hush tube, the bottom of the water supply inlet shall be installed 25mm above the full opening of the overflow pipe. Water closets having the flush valve seat less than 25mm above the flood level rim of the closet bowl shall have the ballcock installed in a separate and isolated compartment of the tank, or provided with a sheathed ballcock, or other equivalent protection.
603.4.3 Water Closet Flushometer Tanks shall be protected against backflow by an approved backflow prevention assembly, device, or method.
603.4.4 Heat Exchangers, and other assemblies or methods of constructions using potable water shall be of listed construction and materials. Water shall be separated from the fluids or gases by a minimum of two separate walls, with a positive, vented leak detection path. The sections in contact with potable water shall be of material and weights suitable for potable water as set forth
603.4.5 Inlets to tanks, vats, sumps, swimming pools, and other receptors, when protected by a listed atmospheric vacuum breaker, shall have such atmospheric vacuum breaker installed on the discharge side of the last valve, with the critical level of not less than 152 mm, or in accordance with its listing, above the flood level rim of such equipment and all downstream piping. Water supply inlets not protected by atmospheric vacuum breakers shall be protected by an approved air gap. Where atmospheric breakers or air gaps are not installed, other backflow preventers suitable against possible contamination or pollution may be installed in accordance with their requirements as set forth in this Chapter.
603.4.6 Lawn sprinkling systems shall be equipped with listed atmospheric vacuum breakers installed on the discharge side of each of the last shutoff valve. Where atmospheric vacuum breakers cannot be installed because of piping elevation or valves, other listed backflow preventers shall be installed in accordance with their requirements as set forth in this Chapter.
- Sec. 261 NPC 1959
- Sec. 262 NPC 1959
- Sec. 263 NPC 1959
603.4.7 potable water outlets with hose attachments, other than water heater drains and clothes washer connections, shall be protected by a listed non-removable hose bibb-type backflow preventer or by a listed atmospheric vacuum breaker installed at least 152 mm above the highest point of usage and located on the discharge side of the last valve.
603.4.8 A listed backflow preventer installed in accordance with the requirements of this Chapter shall protect water-cooled compressors, degreasers, or any other water-cooled equipment. Note: Some water-cooled equipment may produce backpressure and shall be equipped with the approved protection.
603.4.9 Water inlets to water-supplied aspirators shall be equipped with a listed atmospheric vacuum breaker mounted at least 152 mm above the aspirator unit or equipped with a listed backflow preventer installed in accordance with its listed requirements and this Chapter. The discharge shall drain through an air gap. When using the tailpiece of a fixture to receive the discharge of an aspirator, the air gap shall be located above the flood level rim of the fixture.
603.4.10 Potable water make-up connections to steam or hot water boilers shall be provided with a listed backflow protection assembly.
603.4.11 Non-potable water piping: In cases where it is impractical to correct individual cross-connections in the domestic water line, the line supplying such outlets shall be considered a non-potable water line. No drinking or domestic outlets shall be connected to the non-potable water line. Whenever possible, all portions of the non-potable water line shall be exposed, and all exposed portions shall be properly identified in a manner satisfactory to the Administrative Authority. Each outlet on the non-potable water line, which may be used for drinking or domestic purposes, shall be posted: “DANGER-UNSAFE WATER.”
603.4.12 Potable water supply to carbonators shall be protected by backflow protection devices as approved by the Administrative Authority and installed per the requirements of this Chapter.
603.4.13 Backflow preventers shall not be in any area containing fumes that are toxic, poisonous, and corrosive.
