The practical application of balance valves

When the operation regulation of the system adopts centralized regulation (such as variable speed regulation of water pumps), balance valves and self operated pressure differential balance valves cannot be used. Because this regulation is achieved by changing the water volume, it changes the hydraulic condition of the system during regulation. Therefore, if a balance valve is used, it will inevitably cause some valves to work normally, but the system flow rate is too large (exceeding the flow rate corresponding to the heat load at this time), some valves to be fully opened but still cannot meet the flow requirements, and some valves cannot work normally due to the pressure difference at both ends not reaching the starting pressure difference, resulting in chaotic flow distribution. Obviously, centralized regulation of the system cannot be realized due to the existence of the balance valve. At this time, if manual control valve is used, the flow of each branch and user can be increased or decreased in the same proportion when the total flow of the system is increased or decreased, that is, the centralized regulation of the system can be transmitted to each end device. When the operation of the system is adjusted to quality regulation, balance valves and self operated differential pressure balance valves can be used, because this regulation method only changes the water supply temperature and is independent of the hydraulic conditions of the system. That is, without changing the hydraulic conditions of the system, the regulation is transmitted to each user and equipment. By using a balance valve, it can absorb pressure fluctuations in the network and maintain a constant flow rate of the controlled load. The use of balance valves can absorb pressure fluctuations in the network and overcome internal disturbances (changes in resistance inside the controlled loop) to maintain a constant pressure difference applied to the controlled loop. When the system adopts a phased change in flow quality regulation, although the flow remains unchanged in each stage. But if a balance valve is used, the control flow or pressure difference should be set for each flow stage, which brings great inconvenience to operation management, so it is not suitable to use it.