What is the air gap?

Hint: 'Air gap with weir overflow' means 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 water level of the rectangular weir over flow

What is the air gap?

Hint 1: 'Air gap with injector' means a non-mechanical backflow prevention arrangement of water fittings with horizontal injector and a physical air gap of 20mm or twice the inlet diameter (whichever is greater).

Hint 2: #the practical application of this arrangement is in a commercial washing machine.

What is the air gap?

Hint 1: 'Air gap arrangement with minimum size circular overflow' means a non-mechanical backflow prevention arrangement of water fittings with an air gap

Hint 2: Likely to be installed in cold water storage cisterns

What is the air gap?

Hint 1: 'Air gap with interposed cistern' means a non-mechanical backflow prevention arrangement consisting of a cistern with type AG overflow and air gap; the spillover level of the receiving vessel (WC pan) being located no more than 300mm below the overflow pipe, and not less than 15mm below the lowest level of the cistern.

Hint 2: Typical application WC

What is the air gap?

Hint 1: 'Domestic tap gap' The fluid category 2 or 3 risk is present downstream.

Hint 2: Typical application hot and cold taps in a cloakroom

What is the air gap?

Hint 1: 'The higher risk tap gap' where a fluid category 4 or 5 is present downstream

Hint 2: typical application kitchen sink

What is the air gap?

Hint 1: 'Pipe Interrupter' with permanent atmospheric vent' means a non-mechanical backflow prevention device with a permanent unrestricted air inlet, the device being installed so that the flow of water is in a vertical downward direction

Hint 2: typical application found in urinals

What is the air gap?

Hint 1: 'Verifiable backflow preventer with reduced pressure zone' means a verifiable mechanical backflow prevention device consisting of an arrangement of water fittings with three pressure zones

Hint 2: Provide protection against fluid category 4. These devices need specialist competency to install and are notifiable to the water undertaker

What is the air gap?

Hint 1: 'Pipe interrupter with atmospheric vent and moving element' means a mechanical backflow prevention device with an air inlet closed by a moving element when the device is normal use, but which opens and admits air under fault conditions - discharging to atmosphere.

Hint 2: Typical application hose union bib tap, protection against fluid category 4

What types of valves are these?

Hint 1: One of these valves is non-verifiable

Hint 2: The other valve is verifiable

What valve is this?

Hint 1: One of these valves is non-verifiable

Hint 2: the other valve is verifiable

What is this valve?

Hint 1: 'Hose Union backflow preventer' means a mechanical backflow prevention device for fitting to the outlet of a hose union tap, and consists of a single check valve.

What is this?

Hint 1: 'Hose union tap incorporating a double check valve'