Expansion vessels for DHW

Hot water expansion tank – safe and efficient operation of the hot water installation

At the Onninen wholesaler we present a wide range of products in the category of hot water expansion tank/expansion tank, responsible for stabilizing the pressure in domestic hot water installations. In our offer you will find high-class devices from renowned manufacturers - Global Water, Flamco Meibes and Reflex. We invite you to shop!

Diaphragm expansion tank – what is its use?

The expansion tank is one of the most important devices in heating and cooling installations – in domestic hot water systems, underfloor heating, fire protection or solar installations. It is responsible for the safety of the system, protecting against uncontrolled pressure increase in the circuit due to overheating or boiling of water.

The expansion tank allows for the absorption of water with an increased volume, which occurs when it is heated. If the tank is missing in the system, the pressure increases excessively, which can lead to the system leaking or the safety valve being activated. Two types of expansion tanks are usually installed in installations: the expansion tank described here (in domestic hot water systems with gas or oil boilers) and the open one (in central heating systems with solid fuel boilers).

How are expansion vessels constructed for domestic hot water installations?

The construction of the expansion tank consists of a steel tank equipped with a connection to the installation and a valve for filling and releasing gas. The tanks are factory-filled with nitrogen - this is the so-called gas part, which can be filled with air if necessary. Inside the tank there is also a water part, which connects to the domestic hot water installation - both parts are separated by a special membrane made of durable synthetic rubber.

A wide selection of expansion tanks for domestic hot water - only at the Onninen wholesaler

On the onninen.pl website we present an extensive range of diaphragm expansion tanks for domestic hot water systems. The devices are available in various configurations (horizontal, vertical tanks), in many capacities and dimensions. They feature modern technological solutions in the field of safety, reliability and ease of installation, such as:

• universal threaded connections,

• durable butyl inner membrane,

• tanks made of sheet metal resistant to deformation, mechanical damage and corrosion (two-component polyurethane paint coating used)

• Nitrogen filling to maintain the pre-charge pressure longer.

Selected devices are designed for domestic hot water and hydrophore installations. When used with a hydrophore pump, they function as pressure stabilizers and cold water storage tanks. The initial pressure of the gas cushion in the vessel is set below the pump activation point. The pump starts and the vessel begins to fill with water until the set upper pressure is reached. Water intake results in a decrease in pressure in the vessel (by pushing water out using the gas cushion).

Why is choosing the right expansion vessel so important?

Take advantage of the Onninen wholesale offer and choose a hot water expansion tank that will guarantee the proper functioning and safety of the heating system. It is important to use the device together with a second safeguard, which is a safety valve.

We encourage you to check out the entire offer and choose the device that will be perfect for your specific installation!