Kitchen equipment (SS636:2018 Clause 8.3.8)
Most of the kitchen equipment, including dish washer, refrigerator, ice maker and washing machine are installed with mechanical pump to discharge unwanted water out from the equipment. In-order to prevent water contamination when its pump malfunction, double check valves (DCV) must be provided along the pipe(s) line before the tap which is connecting to any kitchen equipment. This is to prevent back-flow which will contaminate the water source.
Storage Water Heater (SS636:2018 Clause 6.5.2)
To prevent mixing of hot water in the storage water heater and back flow of water which will contaminate the water source a double check valve is to be install after a stop valve before the inlet of the storage water heater.
NEWater (SS636:2018 Clause 4.3)
For all property having two source of water supply (potable water & NEWater) a double check valve is required to install at the potable water pipe line to prevent mixing with NEWater during switching over. There shall be no cross connection between the PUB and NEWater supply pipelines.
Firefighting services (SS636:2018 Clause 6.8.4)
A double check valves with drain-out test cocks shall be provided to prevent contamination, the double check valves shall be installed immediately after the branch-off from the potable water pipe to serve the firefighting system.
Drinking fountains/water coolers (SS636:2018 Clause 8.3.6)
Drinking fountains or water coolers shall have an inclined and hooded jet to prevent contamination. Double check valves are to be installed at the pipe supplying water to the drinking fountain/water cooler.
Balancing tank for swimming pool filtration plant (SS636:2018 Clause 8.3.9)
A double check valves are to be installed at the water supply pipe to the balancing tank, this is to prevent back flow and contamination of water source.
Recommendation:
1. Clean your DCV once a month
Picture of DCV
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