More on esbe mixing valves

[@alisoncarney1745]

Well explained andrew ps i cant download app from link on esbe site it says link not found can anybody help?

[@andrewmillwardwatford9410]

@@alisoncarney1745 I think it's not available for the iPhone

[@hufartd]

Any simplification in using a 4 port mixing valve like the viessmann undermount mixers have. i.e do they automatically control authority. Happy to be completely wrong.

[@andrewmillwardwatford9410]

@@hufartd a kvs value is described as the flow rate through a fully open valve in cubic metres per hour with a pressure drop of one bar across the valve. If a valve is adjusted and then retested the result would be different but would be called a KV value. So a radiator valve for example can be adjusted to achieve a different KV value. But the kvs value would be a good indicator of the authority of control over the circuit and it may be difficult to adjust the valve for an accurate KV value if the authority of the valve is too low.

[@andrewmillwardwatford9410]

@@hufartd so for a mixing valve the KV value would not apply in any meaningful way and careful selection of a valve with the correct kvs value is required. Some manufacturers have suggested using a sleeve in the valve that effectively reduces the opening orifice and increases the resistance in the valve effectively lowering the kvs value. These are available for the flamco mixing groups. Flamco have also suggested that by putting a flow restriction in the circuit you can reduce the kvs value. I am convinced that this is an error and would recommend nobody apply this theory