While the pressure tank itself does not typically contain a check valve, the overall water system that includes a pressure tank, especially one drawing water from a well, absolutely requires a check valve to function correctly and maintain pressure.
The Role of a Check Valve in Water Systems
A check valve is a crucial component in many water systems. Its primary function is to allow water to flow in only one direction, preventing backflow. This is particularly important in systems where pressure needs to be maintained, such as those using a pressure tank.
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At the very least, a well pump needs a foot valve (a special kind of check valve) that sits in the water inside the well. A check valve stops water from flowing back into the well, which keeps the pump primed and the pressure tank pressurized.
This highlights that while the check valve may not be on the tank itself, it is essential to the system the tank is part of. The foot valve, located at the bottom of the suction pipe in the well, is a common example of a check valve vital for well systems.
How a Check Valve Supports the Pressure Tank
A check valve ensures the system remains pressurized by preventing water from draining back towards the pump or source when the pump turns off. Here's how this benefits the pressure tank:
- Maintains System Pressure: By stopping backflow, the check valve keeps the water line between the check valve and the house/tank full and under pressure. This is the pressure that the tank helps regulate and store.
- Keeps the Pump Primed: For jet pumps located above ground, preventing water from draining back ensures the pump casing remains full of water, ready to pump the next time it turns on.
- Optimizes Pump Cycling: By holding pressure, the system doesn't lose all its pressure when the pump is off. The pressure tank can then deliver water until the pressure drops to the pump's cut-in setting, allowing the pump to turn on less frequently, which saves energy and extends pump life.
In summary: Although a pressure tank unit doesn't have a built-in check valve, a check valve elsewhere in the system (like a foot valve at the well pump) is indispensable for the system's ability to maintain pressure and keep the tank functioning as intended.
