lesson 11 Flashcards
What is cross connection in plumbing?
- a plumbing connection
- through which contaminants
- from drains, sewers or waste pipes
- can potentially enter drinkable water supply
What is a direct cross connection
when drinkable water system is directly connected to drain, sewer, or non potable water supply
True or false: non potable pipes/sewer pipes are permitted above food prep/food storage areas
false
What are the 2 ways of back flow?
- back pressure
- back siphonage
What is back pressure?
- increased pressure from non potable pipes
- pushes unclean water into potable pipes
What is back siphonage?
- decreased pressure in potable pipes
- allows non potable water to enter into potable pipes
What is the only reliable back flow prevention device?
air gap
What should be the length of the air gap?
- at least 2x the diameter of water inlet
- no less than 1 inch
How must a horse bib type vacuum breaker be attached?
-must be screwed onto threat faucet
True or false - hoses installed on sinks can be submerged in water
false
What is the function of an atmospheric vacuum breaker
to prevent back flow from back pressure/back siphonage
When is the double vent check valve used?
- on soda carbonators
- to prevent backflow of carbonated water
- into water supply pipes
Why must carbonated water not get into pipes?
- it is acidic
- may cause pipes to erode
- may cause metal poisoning
How does doubled vented check valve work?
-allows co2 to escape into air during backflow
8 pieces of equipment requiring back flow prevention
- urinals
- potato peelers
- garbage grinders
- water closets
- steam tables
- ice machines
- dishwashers
- sinks
What is the function of an air break?
- no direct connection
- between sewage systems
- and drains from equipment which has anything to do with food
True or false - an airbreak is not required at hand wash sinks
true
Where must indirect sewer connections be located?
- w/in 2 feet of equipment
- inlet side of grease interceptor
Equipment requiring indirect waste connections
- sinks
- fridges/freezers
- ice makers/storage bins
- steam tables/kettles
- dipper wells
Where does grease interceptor need to be installed?
- waste line from pot washing sinks
- floor drains
- food scrap sinks
- scullery sinks
- scraper section of commercial dishwasher
How much grease should interceptors be removing?
-at least 90 %
True or false: fats, oils, grease are prohibited from being discharged into public sewers
true
Types of vacuum breakers
- hose bib type vacuum breaker
- atmospheric vacuum breaker
What are vacuum breakers?
devices intended to protect against backflow
Difference between air gap and air break
Air break: unobstructed vertical distance through the air separating food related equipment and drain pipes
Air Gap: unobstructed vertical distance through air separating inlet of potable water from potentially contaminated source
