What is a Type AA air gap?
Type AA air gap – air gap with unrestricted discharge A non-mechanical backflow prevention arrangement of water fittings where water is discharged through an air gap into a receptacle which has at all times an unrestricted spillover to atmosphere.
What is the minimum separation of a correctly installed air gap?
The minimum required air-gap separation shall be measured vertically from the lowest end of the potable water outlet to the flood rim of the receptacle into which the potable water discharges. This air-gap distance shall be a minimum of twice the effective opening (0) of the potable water outlet.
What should the air gap be?
Water softener air gap Water softeners require an air gap of at least two inches between their drain hose and the dedicated drain.
What is a type Ag air gap?
Type AG – Air gap arrangement with minimum size circular overflow. A non-mechanical backflow prevention arrangement of water fittings with an air gap; together with an overflow, the size of which is determined by measure or a vacuum test.
What type of air gap is incorporated over a kitchen sink?
Sink taps require an AUK 3 air gap (20mm or twice the inlet bore diameter, whichever is greater above the spill-over level).
Do washing machines have backflow prevention?
Most “domestic” – meaning intended for use in a house – clothes and dish washing machines are manufactured with a built-in backflow prevention device or arrangement suitable for Fluid Category 3.
What type of standard backflow prevention is required for a domestic bath?
fluid category five backflow protection
Baths and hand-basins in premises where healthcare is provided (e.g. hospitals, nursing homes) or for use in connection with medical, dental or veterinary purposes, require fluid category five backflow protection.
Does washing machine drain hose need air?
It is important to have a sizable air gap between the end of the drain hose, and the bottom of the sink. An air gap prevents backwater from ever getting sicked back into your washing machine.
How do you vent a washing machine drain pipe?
Bend the tip of the drain hose into a U-shape, then hook it up to the drain hole beside the water inlet valve. The drain hole should then be connected to the main ventilation pipe. Install an AAV, or air admittance valve, on the drainage pipe to control the air pressure when you drain.
What size hole is needed for air gap?
1-3/8″
NOTE: If your sink does not have an unused hole for mounting the air gap body, bore a hole 1-3/8″ (3.5 cm) in diameter next to the sink using an electric drill and hole saw. Remove the cover and collar from the top of the air gap body.
Where is there an air gap in a mains pressure water system in a building?
A simple example is the space between a wall mounted faucet and the sink rim (this space is the air gap). Water can easily flow from the faucet into the sink, but there is no way that water can flow from the sink into the faucet without modifying the system.
How many types of backflow preventers are there?
Backflow preventers generally come in two different types: backflow prevention devices and backflow prevention assemblies.
How do you vent a washer drain line?
What is a type AB air gap?
Type AB air gap is formed by an arrangement of an air gap and spillover slot. The Water Regs UK type AB air gap calculator tool is an easy-to-use design aid for designers and installers.
What is the water regs UK type AB air gap calculator tool?
The Water Regs UK type AB air gap calculator tool is an easy-to-use design aid for designers and installers. It provides details of the height of the spillover slot; the air gap distance between the inlet valve and the critical water level; and as the calculation method is used rather than the test method, three validation criteria.
What is AA type backflow protection?
A non-mechanical backflow prevention arrangement of water fittings where water is discharged through an air gap into a receptacle which has at all times an unrestricted spillover to atmosphere. Maximum permissible fluid category against which a Type AA air gap is accepted as adequate backflow protection:
What is an air gap with weir overflow?
See Diagram 1 TYPE ‘AB’- Air gap with weir overflow. A non-mechanical backflow prevention arrangement of water fittings complying with Type ‘AA’, except that the air gap is the vertical distance from the lowest point of the discharge orifice which discharges into the receptacle, to the critical level of the rectangular weir overflow.