Hydrofor is a colloquial term for a water-and-air installation designed to maintain constant water pressure. An integral part of a hydrofor system is a pressure tank filled with liquid and air, as well as an impeller pump. The hydrofor tank is connected to the water supply system and equipped with a pressure gauge for measuring pressure. Hydrofor systems are used primarily in single-family homes and allotment gardens, but these are not their only applications. They are also successfully used in industrial plants and service establishments.
When is it necessary to install a hydrofor system?
Most private properties have a connection to the water and sewage network. However, there are situations when no such connection is available and the property owner must supply themselves with water, for example by using an underground water intake, such as a deep well. In such cases, the proper functioning of the domestic water system directly depends on the installation of a hydrofor system. It is responsible not only for maintaining optimal water pressure, but also for protecting the pump from excessive operation, meaning switching on and off too frequently. Traditional non-diaphragm hydrofor systems are characterized by their considerable size, but more compact membrane hydrofor systems are portable and operate more quietly, and their capacity is usually between 50 and 100 liters. Another solution is a set of two tanks—one for water and the other for air—that work together with the help of a compressor.
A hydrofor system is also installed in single-family homes with access to the water supply network when the water pressure at the tap is too low. A hydrofor system can also be used to draw water for watering garden plants—it can draw water not only from a well but also from a rainwater tank. It is also an excellent solution when a summer house needs to be supplied with water. The hydrofor system accumulates pressure and stores a reserve of water that meets users’ needs while the pump is not operating.
How does a hydrofor system work?
The operating principle of a hydrofor system is not complicated and relies on differences in pressure. Hydrofor systems work with self-priming pumps or deep-well pumps. The cylindrical hydrofor tank is partially filled with water, with compressed air above it. Drawing water from the tank into the water supply network causes the air to expand and its pressure to decrease. The pressure difference is controlled by a pressure switch and measured with a pressure gauge. When the air pressure reaches its minimum value, the pump switches on. The electric motor drives the impeller in the pump, whose movement increases the angular momentum of the liquid. This creates a pressure difference between the suction and discharge sides of the pump, making it possible to force water from the well into the hydrofor tank. The air begins to compress, and its pressure increases as the amount of water drawn in increases. A check valve prevents water from flowing back into the well.
Once the maximum air pressure is reached, the pressure switch turns off the pump, and the water can be distributed through the water supply network. Put simply, the increasing air pressure presses on the water and “pushes” it into the water system when the tap is turned on. The loss of water is equivalent to the expansion of the air, causing its pressure to drop—and the cycle can begin again.
