Check Valve
- Thread starter maltaron
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Check valves are used to prevent backflow within a water pipe.
Double check valves are used where the Water Regulations would require backflow prevention to "fluid category 3", for example a garden tap or basin/bath where the tap outlets are below the spillover level and may become submerged. They are also used before the filling loop for a boiler.
Single check valves are used to prevent backflow in lower risk applications where the requirement is not as high - for example on the hot and cold supplies to a mixer tap or shower to stop mains pressure cold pushing up gravity fed hot, or pumped hot pushing back into the cold.
Single check valves can also be used on washing machine feeds to stop water from cheap rubber hoses pushing water back that has a slight TCP taste.
The type of check valve you need is determined by what will be fitted after it.
Double check valves are used where the Water Regulations would require backflow prevention to "fluid category 3", for example a garden tap or basin/bath where the tap outlets are below the spillover level and may become submerged. They are also used before the filling loop for a boiler.
Single check valves are used to prevent backflow in lower risk applications where the requirement is not as high - for example on the hot and cold supplies to a mixer tap or shower to stop mains pressure cold pushing up gravity fed hot, or pumped hot pushing back into the cold.
Single check valves can also be used on washing machine feeds to stop water from cheap rubber hoses pushing water back that has a slight TCP taste.
The type of check valve you need is determined by what will be fitted after it.
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