In any closed loop system with pipes and tanks, having air and dirt inside is unavoidable. Water vapor inside the system can condense and accumulate, where it can be removed with the use of a valve. However, cleaning dirt and removing air would need a separate system.
Since the mid-2000s, the development of the hydraulic separator or a low-loss coupler or de-coupler has made dirt and air removal a single integrated process.
The Nature of Air
Air naturally dissolves in a liquid. The exact volume of air depends on the system pressure and temperature. When the temperature decreases, bubbles will form and can be bled out of the system. However, a closed system usually has pressure, which does not decrease while in operation.
In addition, during maintenance or whenever the system is shut down, the gas, in the form of microbubbles, do not necessarily evaporate or bleed out. The air that gets into the system remains inside the pipes and tanks. This results in a decrease in efficiency across the system.
Cooling and heating systems depend on a de-coupler to reduce flow velocity inside the vessel. This allows air and dirt removal in a single device. Other functionalities can be added, including hydraulic separation and magnetic dirt removal. For older systems, having the capability for magnetic dirt removal is a bonus. This can help remove iron and steel particles from inside the vessels and pipes.
While the primary use of a hydraulic separator is for hydraulic separation, this also has other features. One of these is called the “coalescing media”, which enhances the ability to separate air microbubbles and prevents them from passing through and floating up to the upper portion of the separator.
The de-coupler is a simple device that has become multi-functional within the scope of a hydronic system. This is an improvement over the traditional methods of a primary and secondary piping and can be integrated into existing systems.