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Food and Drug Administration
and
Conference for Food Protection
FOOD ESTABLISHMENT PLAN REVIEW GUIDE |
SECTION III
FOOD ESTABLISHMENT GUIDE FOR DESIGN, INSTALLATION, AND CONSTRUCTION RECOMMENDATIONS
Plumbing shall be sized and installed according to applicable codes. There shall be no cross connections between the potable water supply and any nonpotable or questionable water supply. Where nonpotable water systems are permitted for purposes such as air conditioning and fire protection, the nonpotable water must not contact directly or indirectly: food, potable water or equipment that contacts food or utensils. The piping of any nonpotable water system shall be durably identified so that it is readily distinguishable from piping that carries potable water.
SUBMERGED INLET PROTECTION
A cross connection is defined as any connection or structural arrangement between a potable water system and a non-potable source, liquid or otherwise, through which backflow can occur.
Backflow is defined as the flow of water or other liquids, mixtures, or substances into a potable water system from any source, other than the intended source.
A connection to a sewer line may be direct or indirect:
* A direct connection is a solid physical joining to a waste or soil line;
* An indirect connection is other than a solid physical joining to a waste or soil line (such as a submerged inlet).
An indirect connection may be one of two types:
* An air gap means the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or outlet supplying fixture, or other device, and the flood level rim of the receptacle. The vertical physical separation shall be at least two times the inside diameter of the water inlet pipe above the flood rim level, but shall not be less than one inch.
* An air break is a piping arrangement in which a drain from a fixture, appliance, or device discharges indirectly into another fixture, receptacle or interception at a point below the flood level rim. The connection does not provide an unobstructed vertical distance through the free atmosphere and is not solidly connected, but precludes the possibility of backflow to a potable water source into a sink or dishwasher/or fixture being drained. See figure #12-5.
There shall be no cross connections between the potable water supply and any non-potable water supply. The potable water system shall be installed to preclude the possibility of back flow and back siphonage. Devices shall be installed to protect against backflow and backsiphonage at all fixtures and equipment unless an air gap is provided. The air gap must be at least twice the diameter of the water supply inlet, but not less than 1", between the water supply inlet and the fixture's flood level rim. See figure #12-1 & #12-2.
The following provides examples of some of the types of equipment with potentially submerged inlets and required backflow/backsiphonage protection:
| Equipment | Backflow/Backsiphonage Preventer Required in Lieu of Air Gap |
| 1. Boiler with chemicals added | Reduced pressure device |
| 2. Boiler with no chemicals added | Air vent type backflow preventer |
| 3. Carbonators for beverage dispensers | Approved backflow preventer (in agreement with local plumbing codes) |
| 4. Lawn sprinkler system with no chemicals added | Atmospheric or pressure vacuum breaker |
| 5. Flush valve toilets | Atmospheric or pressure vacuum breaker |
| 6. All hose bibs inside & outside of establishments | Hose bib-type vacuum breaker |
| 7. Preflush hose with a nozzle head that may be submerged | Pressure vacuum breaker |
| 8. Perforated pipe to oriental wok cookers | Atmospheric vacuum breaker |
| 9. Inlets which are or may become submerged: | |
| Atmospheric vacuum breaker* | |
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| Soap portioner must contain an internal air gap | |
| Air vent type backflow preventer (RPZ may be required if toxic chemicals are added) |
See figure #12-3 for examples of backflow/backsiphonage prevention devices.
*An atmospheric vacuum breaker means a mechanical device which automatically air vents a pipeline to prevent backsiphonage. The device shall be located beyond the last control valve prior to the first outlet and at an elevation 6 inches higher than any source of contamination. Atmospheric vacuum breakers shall be installed so that they are not subject to backpressure or continuous operating pressure of more than 12 hours duration.
DRAINS
A direct connection may not exist between the sewerage system and any drains originating from equipment in which food, portable equipment, or utensils are placed, except if otherwise required by state plumbing codes. When a warewashing machine is located within 5 feet of a trapped floor drain, the dishwasher waste outlet may be connected directly on the inlet side of a properly vented floor drain trap. See figure #12-4.
Other examples of required indirect drain line connections are:
| Equipment | fIndirect Drain Line Connection Required to Sewer Line |
| 1. Water-cooled condenser for ice machine or other refrigeration system | Air gap |
| 2. Air-cooled condenser for ice machine or other refrigeration system | Air break |
| 3. Ice bin | Air break |
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