In order to ensure good stability of control, it is essential for a control valve to have an equal percentage characteristic. This type of characteristic produces a linear variation in thermal output according to the amount of opening of the valve (also known as the system characteristic). Under normal testing conditions a conventional ball valve exhibits an S-shaped characteristic. When it is installed in a real
system, however, this characteristic is seriously
deformed because, compared with its nominal
size, a ball valve possesses an extremely high flow
coefficient. Whether used with or without pipe
reducers or a reduced bore, they do not normally
allow stable regulation of the thermal capacity.
Belimo's unique Characterized Control Valve (CCV) is very different. A special characterizing disc inside the valve gives it an equal percentage characteristic which is comparable with that of a globe valve of the same nominal size. The flow (the Cv value) is reduced
to the required value by a combination of the hole in the ball and the shaped aperture in the disc. The increase in flow as the valve is opened
is very slow and controlled.
This produces better part-load behavior and improved stability of control while also optimizing energy consumption.
This valve is typically used in air handling units on heating or cooling coils, and fan coil unit heating or cooling coils. Some other common applications include Unit Ventilators, VAV box re-heat coils and bypass loops. This valve is suitable for use in a hydronic system with variable flow.
Suitable Return Actuators for the B217 Type CCV Valve Include:
- TR Series (Non-Spring)
- LR Series (Non-Spring)
- NR...N4 Series (Non-Spring)
- TF Series (Spring)
- LF Series (Spring)