In many water systems, pressure tanks pump water smoothly. These are vessels that hold water under pressure. This provides a stable water flow and protects the pumps. This guide covers how pressure tanks work, their types, how they can be used, and the care that needs to be taken.
What Is a Pressure Tank?
A pressure tank is a closed vessel. It has water on one side and a cushion of air on the other. This air expels water when a tap opens. The tank ensures that the pump isn’t turned on and off too frequently.
Key ideas:
- Useful for maintaining water under certain pressure.
- It reduces pump cycling.
- It releases stored water as needed.
How a Pressure Tank Works
Pressure tanks use air pressure to function. The pump fills the tank with water while running. This water is pressing up against the air cushion. Air compresses and stores energy.
Air expands when the water flows out. This maintains pressure until the tank is at its low end. Then the pump turns on again. A pressure switch determines when the pump runs and when it is off.
Main steps:
- Pump water into the tank until the cut-off pressure is reached.
- Air is compressed, and then it is pushed by the water.
- When people use water, it expands air and pushes water out.
- The pump restarts at cut-in pressure.
Types of Pressure Tanks
There are a few basic designs of pressure tanks. Each architecture has its own approach to air and water.
1. Air-Over-Water Tanks
These tanks have one chamber. Air and water are in the same space. They are simple and cheaper. But air can lose its energy and dissolve into water over time. That reduces the tank’s potential effectiveness. Sometimes users need to manually add air.
2. Bladder Tanks
Bladder tanks hold water inside a rubber sleeve. Space around the sleeve is filled with air. The sleeve isolates water from air. This prevents air from getting into the water. Bladder tanks require less maintenance than air-over-water types.
3. Diaphragm Tanks
In diaphragm tanks, a flexible membrane is utilized. This membrane separates water and air in the tank. It works like a bladder. In some instances, diaphragm tanks have a longer life. They also stop air and water from getting mixed.
4. Automatic Air Volume Control (AVC) Tanks
AVC tanks use a float or valve system. This system automatically maintains the correct air volume inside. It reduces manual air charging. This functionality is particularly fit for larger systems requiring low maintenance.
Benefits of Pressure Tanks
Pressure tanks offer many benefits. They improve water flow and save pump life.
- Steady Water Pressure: They even out fluctuations. Water does not pour in bursts or drips. This makes the showers and taps feel steady.
- Pump Protection: Tanks reduce the number of starts and stops of a pump. A pump has a longer lifespan when it doesn't cycle too frequently.
- Energy Savings: A pump that runs fewer times uses less energy. The tank stores energy in the form of compressed air.
- Backup Water Supply: In the event of a power failure or pump failure, the tank still retains a small amount of water. It can provide temporary access to water.
Where Pressure Tanks Are Used
There are many applications where pressure tanks are suitable. They accommodate both small homes and sprawling factories.
- Homes with Private Wells: Tanks keep taps steady in single-family homes. They are used with well pumps for 30–50 psi of pressure.
- Farming and Irrigation: Tanks maintain a constant flow to sprinklers and drip lines on farms. Tanks are also useful when maximizing pump operation, as they are not constantly running.
- Commercial and Industrial Systems: Factories and offices use them in heating and cooling loops. They are also used on process water lines to eliminate pressure swings.
How to Choose the Right Tank
Selecting a tank involves several steps. Use this information to determine the appropriate tank size and type for your system:
- Pressure Settings: Choose tanks rated for the system cut-in and cut-off pressures.
- Drawdown Capacity: This is the amount of water that the tank can provide outside of pump cycles. Bigger tanks provide more drawdown.
- Flow Rate Matching: The pump should run for about one to two minutes per cycle, so the tank capacity should allow the pump to cycle accordingly. Too short cycles deplete pumps.
- Space and Orientation: Vertical tanks fit small floors. Horizontal tanks go under low ceilings.
Installation and Care
A tank must be installed and maintained in the right way. This keeps it working well.
Proper Installation
A tank is placed on something firm and level by the pump. It has to be fitted with proper pipe fittings. Follow local plumbing codes.
Regular Checks
Check the tank every few months. Check for dings, rust or leaks. Keep an eye on pipe connections and the pressure switch.
Air Pressure Test
Turn off the pump. Drain the water to allow the air side to fill. Check air pressure with a tire gauge. It ought to be several pounds or so below the pump cut-in pressure. Top off with air if necessary with a bicycle pump or a compressor.
Draining and Cleaning
Open a drain valve to clear out sediment. They can accumulate sediment over time. Cleaning helps keep the tank functioning properly.
FAQs
How often should the tank’s air pressure be checked?
Every six months, a tank’s air side should be tested. When the reading is low, it might require air.
Can a homeowner install a pressure tank?
A bladder tank can be installed by a homeowner with plumbing experience. Systems that are complex or high-pressure might require a pro.
Why does the tank become waterlogged?
Waterlogging occurs when air comes out of solution or the bladder ruptures. Minor cases can sometimes be remedied by draining and adding air. Significant damage could require the tank to be serviced or replaced.
Summary
Tanks provide pressure to water systems. They maintain steady pressure and protect pumps. They use less energy and serve as a backup for water. Getting the type and size right is an important part. Routine checks of air pressure and the condition of the tank keep things running smoothly. A pressure tank will last many years and provide reliable water delivery with proper maintenance.