During commissioning of heating and cooling systems, hydraulic balance is often achieved using balancing valves; static or dynamic
During commissioning of heating and cooling systems, hydraulic balance is often achieved using balancing valves. Two types of these valves exist: static and dynamic balancing valves.
Static balancing valves serve as a permanent resistance, built into the system. The settings for these valves must therefore be calculated and adjusted accurately, as changing just one of them in the system could change the flow through all other valves.
Dynamic balancing valves work as flow limiters. They are set to a desired flow rate and ensure that a larger flow rate does not take place. If the pressure in front of the valve increases, it will close some more, so the pressure loss across the valve becomes correspondingly higher. This maintains the desired flow rate in the specific path.
The inlet pressure for a dynamic balancing valve needs to be higher than a certain limit for it to operate properly. This means that the resistance at the most distant valve cannot be close to zero, as is the case with static valves.
Balancing valves are available from numerous manufacturers. Some of these provide electronic measurement equipment that allows measuring the flow through their valves. This is done by measuring the pressure loss across the valve and calculating the flow according to the kv-value of the present position of the valve.