A vacuum breaker prevents potential water contamination by stopping water from flowing backwards.
What is backflow?
Backflow occurs when water flows in the reverse direction. Imagine water flowing back into your faucet, instead of flowing outside like normal.
How can backflow occur?
Normal water pressure keeps water flowing in one direction. For backflow to occur, the pressure needs to drop so much that it creates suction and pulls the water backwards. That’s not a problem with clean water. But you certainly don’t want any dirty or hazardous water flowing backwards into your home.
A few common situations that lead to backflow:
1. A main water pipe bursts
2. A water pressure jet is connected to the water main and draws a high volume of water
3. Unauthorised installation of inline Booster Pump
What is a vacuum breaker?
A vacuum breaker is a backflow preventer. It’s a threaded device that attaches to a faucet. It prevents water from flowing backwards into the plumbing system.
How does a vacuum breaker stop backflow?
The pressure of flowing water pushes the valve open. When the water is turned off, the pressure decreases and the valve closes. The air pressure keeps water from seeping back into the spigot from the outside.
Do I have a vacuum breaker?
Is there a device screwed onto your faucet’s mouth similar to the one pictured shown? If so, you do have a vacuum breaker.
Do I need a vacuum breaker?
Under the Singapore Standard SS636,
Handheld bidet spray (SS636:2018 Clause 8.3.3)
To prevent water being drain back into the water source when the hand-held bidet spray (connected to a flexible hose) submerge into the water closet reservoir, thus all hand-held bidet spray (connected to a flexible hose) located next to a water closet shall be installed with a check valve and vacuum breaker.
Draw-off taps near a pond or drain (SS636:2018 Clause 8.3.4)
To prevent water being drain back into the water source when the hand-held spray (connected to a hose) submerge into the pond from a draw-off tap, all draw-off tap installed near to a pond or drain shall be installed with a check valve and vacuum breaker.
Please Note
It is common to see water coming out from the vacuum breaker and this shows that the vacuum breaker is performing its function by preventing water from entering into the main water source.
Picture of VB
PUB Mandatory test required
Material toxicity test on Non-Metallic part (Plastic)
SS375 – Suitability of non-metallic products for use in contact with water intended for human consumption with regard to their effect on the quality of the water
Material toxicity test for Matellic part (Metal)
AS/NZS4020 – Testing of products for use in contact with drinking water
Performance test require
BS5154 – Dimensions and tolerances of body ends and pressure testing
BSEN14451 – Devices to prevent pollution by backflow of potable water for in-line anti-vacuum valves