Where traditional radiator flow rates must be set through manual balancing, radiator valves with a variable Kv (pre-settable) can be set to the correct peak design flow rate. However, despite radiators with pre-settable TRVs being balanced correctly in full load, they will inevitably experience differential pressure variations as other TRVs close (part load). These pressure fluctuations will result in over and underflow, resulting in poor occupant comfort. Pressure independent thermostatic radiator valves (PI-TRVs) incorporate their own integral differential pressure controller (DPCV) ensuring a maximum flow limitation in both part- and full load.
The Pt40 PI-TRV balances the heating system 24 hours a day, 365 days a year. Maintaining a low return temperature at all loads minimises energy waste, which results in cost-effective heat delivery. Achieving this requires pressure independent flow control that dynamically balances the heating system.