Expansion vessel

Types of Expansion Vessels

Membrane Expansion Vessels

These vessels use a flexible membrane to separate water and air, preventing air from entering the system and thus ensuring exceptional operation without issues caused by water bubbles in the system.

Diaphragm Expansion Vessels

With rubber diaphragms, these vessels are ideal for heating and potable water systems.

Interchangeable Membrane Expansion Vessels

They allow the replacement of the membrane, which extends the lifespan of the vessel without needing to change the expansion vessel. This is a popular option among our customers, although it may not be compatible with all types of applications.

Stainless Steel Expansion Vessels

Expansion vessels made of stainless steel have greater resistance to higher liquid flows while being able to withstand higher pressures in systems that require high operating pressure to pump water to complex circuits.

Applications of the Expansion Vessel

Expansion vessels are vital components in various systems, as they allow the management of pressure excesses in any DHW circuit. Here we explain where they are installed in each of them:

Boiler

Expansion vessels for the boiler are installed in the heating circuit pipe, usually before entering the boiler, to prevent damage to the internal water heating system and extend the boiler's life. This allows the expansion of hot water as it heats up without exerting excessive pressure on the system, thus providing better climate control free of air bubbles or pressure variations in the home's climate control circuit.

Electric Water Heater

If you have an electric water heater to heat water at home, the expansion vessel is placed inside the appliance, usually near the thermostat, to serve as an escape route for possible pressure variations in the DHW circuit, although it will automatically adjust along with the pressure regulator without human intervention. This allows the water to expand when heated without damaging the electric water heater and ensures the distribution of water in the shower.

Solar Energy

In solar energy systems, the expansion vessel is placed in the heat transfer fluid circuit that circulates between the solar panels and the storage tank. This prevents pressure build-up in the system when solar radiation is high, thus attempting to store and heat as much water as possible, to later supply it to the connected DHW system.

Benefits of Installing an Expansion Vessel

Installing an expansion vessel brings significant advantages, as it will benefit our shower comfort and extend the lifespan of the devices we use to heat water in our home:

• Increased Durability: By allowing water to expand and contract without creating excessive pressure in the system, expansion vessels prolong the lifespan of your equipment, such as boilers and electric water heaters.
• Energy Efficiency: They maintain the efficiency of your heating or solar energy system by preventing components from deteriorating due to pressure.
• Fewer Repairs: By reducing premature wear of components, maintenance needs and costly repairs are minimized.
• Safety: They prevent dangerous pressure build-up in the system, which can prevent leaks and costly damage.
• Energy Savings: By maintaining consistent and efficient performance, they help reduce energy costs over time.

Where to Install the Expansion Vessel

The expansion vessel used in DHW installations can practically be found in all installations parallel to the device responsible for heating the water, whether it is a boiler, electric water heater, heater, or another device in our installation.

Each installation has its peculiarities, whether due to its complexity or the needs demanded by each system.

What to Consider When Choosing an Expansion Vessel

When choosing an expansion vessel, we must consider various variables that will be fundamental in having a DHW system that meets our needs:

• The required capacity: Once we know the capacity our DHW system will have, we can install an expansion vessel according to the needs, as if it has a high volume of litres, we should opt for a model with greater capacity.
• The working pressure: Depending on the pressure to which the DHW circuit must be subjected, it will be advisable to use an expansion vessel made of more durable and robust materials, to avoid leaks, breakages, or malfunction.
• The type of fluid: Understanding that it will not be the same if water circulates at high temperatures or refrigerant liquid, we must choose the appropriate material.
• The environmental conditions: Based on the climatic conditions of the place where we will install the DHW system, it will be important to choose according to the needs that may arise in winter, to have the climate control system in full operation without interruptions.
• The heating device we will use: Depending on the device we use to heat water (electric water heater, boiler, heater), we will need to take certain measures when acquiring the expansion vessel, as each device will require minimum specifications for proper operation.