Expansion tanks are very important in terms of keeping the pressure in the system under control and providing the required amount of water to the system. Expansion tanks are mainly two types, open and closed.
Open expansion tanks are open to the atmosphere. In this system, expansion tanks are placed higher than the highest point of the distribution system in order to collect the expanded water. The water expanding in the boiler is collected in the expansion tank by means of a safety pipe. The expansion tank also keeps the system open to the atmosphere and ensures safe operation of the system by preventing the pressure in the installation.
However, open expansion tanks have been replaced by closed expansion tanks over time. Closed expansion tanks are used with a safety valve and manometer. These tanks are usually membrane. Boilers in which these tanks are used should be boilers providing automatic controlled combustion. Today, closed expansion tanks are mostly used. Because the heating system is turned to a closed system and corrosion will be lower as it will not be in contact with air. In the system, the water evaporates and does not disappear, so the water never decreases. Since the pressure distribution in the system will be equal, the heating to be obtained is more balanced.
Expansion tanks are covered in the article entitled Pressure vessels and installations in the Regulation on Health and Safety in the Use of Work Equipment. Hydrostatic tests are carried out mainly in the control of expansion tanks. Accordingly, the checks must be carried out at least once a year and during the checks, if there is no contrary provision in the standards, the 1,5 multiple of the operating pressure must be applied.
In addition to the regulation mentioned in the control works, other legal regulations such as the regulation of pressure equipment, the regulation of portable pressure equipment and the regulation of simple pressure vessels are also taken into consideration.
Our company carries out periodic controls and inspections of expansion tanks within the scope of regular controls of pressure vessels in accordance with the relevant legal regulations and standards published by domestic and foreign organizations. These standards are based on a few standards:
- TS 1203 EN 286-1 Tanks - Simple - Non-flammable - Pressurized - Designed to store air or nitrogen - Part 1: Pressure tanks for general purposes
- TS EN 13445-5 Pressure receptacles - Non-contact - Section 5: Inspection and testing