To achieve the design return temperatures the system should be properly balanced and time of commissioning, and have fitted control valves that will maintain that balance during operation.
The Inta PTRV is a radiator valve that performs the functions of a thermostatic valve and a differential pressure regulator.
Each pre-settable thermostatic valve comes with six pre-set Kv values.
The valve comes complete with the EN215, class A efficiency rated Inta i-therm TRV valve
head.
Reference CP1 2020 code of practice
Most efficient. Inlet at top, out at bottom.
Both valves on the same side of the radiator
Configuration for long radiators.
Inlet always at the top.
The code does not advise connections both at the bottom of the radiator, as efficiency drops by over 10%.
The flow rate pre-setting limits the maximum flow passing through the radiator and thereby ensures simple and effective radiator circuit balancing. The differential pressure regulator integral with the rad valve maintains a constant pressure differential so therefore maintaining the set flow rate.
Pre-settable dial up Kvs settings for PTRV | Thermostatic head temperature settings |
||
---|---|---|---|
1 | 25 l/h | * | 7°C |
2 | 35 l/h | 1 | 10°C |
3 | 55 l/h | 2 | 15°C |
4 | 80 l/h | 3 | 20°C |
5 | 95 l/h | 4 | 25°C |
6 | 120 l/h | 5 | 30°C |
Heat Load W | Flow l/h | Kv Setting | |
---|---|---|---|
600W | 20°C | 25 | 1 |
800W | 20°C | 34.5 | 2 |
1200W | 20°C | 53.88 | 3 |
1800W | 20°C | 77.85 | 4 |
2200W | 20°C | 94.8 | 5 |
2800W | 20°C | 120.68 | 6 |
Examples for setting the PTRV, min pressure for constant flow 0.1 bar. Heating is 60/40 with calculated *flow rated using the formula:
Position | Flow rate (l/h) |
---|---|
1 | 25 |
2 | 35 |
3 | 55 |
4 | 80 |
5 | 95 |
6 | 120 |
The values required for pre-setting the PTRV can be easily set by using the adjustment tool available as an accessory. Set the flow rate that is to be kept at a constant value by selecting the corresponding number on the
pre-setting scale on the body of the valve.
Heating load = 600W
For this example, the ΔT is 15°C
Formula
Calculation
Minimum pressure to maintain constant flow = 10 kPa (0.1 bar). Set position 3