A faucet check valve, also known as a backflow preventer, is a device used in drinking water installations within sanitary and building faucets to prevent the reverse flow of water. This is crucial for maintaining the purity and safety of the potable water supply.
Understanding Check Valves
Check valves are essential components of plumbing systems. They are designed to allow water to flow in only one direction, hence preventing:
- Backflow: The reversal of water flow in a pipe.
- Back Pressure: Water from a secondary source pushing back into the main supply.
- Back Siphonage: A vacuum pulling used water back into the potable water system.
How Check Valves Function in Faucets
According to DIN EN 13959, check valves in faucets are primarily utilized to protect the drinking water system from contamination. The reference states that check valves are, "used in sanitary and building faucets of drinking water installations. They keep the pipework free of unwanted backflow, back pressure or back siphonage of used water, and protect the drinking water system from contamination." Here’s a breakdown of their functions:
- Preventing Contamination: By ensuring water flows only one way, check valves stop potentially contaminated water from re-entering the clean water supply.
- Maintaining Water Quality: They help preserve the quality of drinking water by stopping the backflow of used or unclean water.
- Ensuring System Integrity: These valves safeguard the plumbing system by preventing water pressure fluctuations that could cause damage.
Types of Check Valves
While there are various designs of check valves, some of the more common ones include:
- Swing Check Valves: These valves use a flap or disc that swings open to allow flow in one direction and closes when flow reverses.
- Lift Check Valves: These valves use a disc that lifts up and down to regulate flow.
- Spring-Loaded Check Valves: These use a spring to keep the valve closed and require a certain level of pressure to open, useful in low-pressure systems.
Practical Applications and Benefits
Here are practical reasons why check valves are crucial in faucets:
- Household Safety: In a home environment, a check valve in a kitchen faucet can prevent soapy water from flowing back into the clean water pipes.
- Commercial Use: In commercial settings, they are equally important to prevent cross-contamination in drinking water systems.
- Legal Compliance: In many regions, the use of backflow preventers or check valves is mandated by building and health codes.
- Increased Reliability: Check valves can extend the lifespan and reliability of plumbing systems by preventing damage from backflow.
Example
Let's imagine your home has a garden hose connected to your outdoor faucet. If a drop in water pressure occurs in the main line while the hose end is submerged in a bucket of soapy water, without a check valve, that soapy water could be drawn back into your drinking water system. A check valve prevents this, keeping your water supply safe.
In summary, a faucet check valve is a crucial component that maintains water safety and system integrity by preventing the reverse flow of water. They are essential for ensuring drinking water systems remain free from contamination.
