Caleffi Thermostatic Balancing Valve
The Caleffi 116 series thermostatic balancing valves (aka automatic balancing valve) are used to automatically balance the various branches of a domestic hot water circulating systems to ensure that all parts of the system reach the required temperature, as well as prevent the growth of Legionella and limit heat losses.
The recirculation circuits are usually sized according to the flow rate required for each branch, based on the allowed heat loss and the corresponding decrease in temperature along the pipe. Generally speaking, the maximum allowed temperature drop between the point of departure from the heating plant and the point of return to the latter is 5°C.
On reaching the set temperature, the obturator, governed by an internal thermostat, modulates the closure of the hot water orifice, thereby aiding circulation towards the other connected circuits. If the temperature decreases there is the opposite action and the orifice reopens.
Temperature setting is easy – simply turn the knob to the desired temperature. Once set, it is possible to remove the cap and place it over the locking slot to avoid accidental tampering of the setting.
If for instance a water temperature of 55°C is needed, the valve is set to the temperature of 55°C. If the temperature of the circulating water is below 55°C, valve opens and more water will pass through. If the temperature is higher than 55°C, the valve closes.
The valve is supplied with a temperature gauge which allows for a quick check that the valve is balancing the water to the correct set temperature.
BENEFITS OVER TRADITIONAL MANUAL BALANCING
There are a number of benefits of using a thermostatic balancing valve over a manual balancing valve in hot water circulating systems. Some of the main features include;
The cost of commissioning is significantly reduced.
Thermostatic balancing valves are ‘field adjustable’ and do not require any special equipment. With a simple and easy ‘set and forget’ installation and no experience required for commissioning, this greatly reduces the cost and time of commissioning. Manual balancing valves generally requires expensive equipment (a manometer) and may require experienced commissioning companies to balance the system to ensure the correct flow rates.
Accurate balancing of hot water on the return lines.
A common issue with balancing a system manually is that installers do not know the correct procedure to balance the system, and so often commissioning is a ‘trial and error’ exercise (or not done at all) which results in uneven distribution of hot water. Thermostatic balancing valves are accurate to within +/- 2°C of the set temperature which ensures thermal balance throughout the system and minimal lag for hot water delivery.
Dynamic balancing of the system is achieved.
A thermostatic balancing valve will automatically adjust to the fluctuating demands of the hot water system, thereby distributing the hot water evenly throughout the day as the demand varies on each circuit. Unlike a manual balancing valve, staged openings do not affect thermostatic balancing valves. Thermostatic balancing valve will simply adapt to any changes within the system, whereas a manual balancing valves will need to be re-balanced and commissioned any time the system is changed and can be very costly and time consuming.
CONSIDERATIONS FOR USE
The thermostatic balancing valve is only available in 20mm, and is suitable for flows up to approx. 0.1l/s, which is generally sufficient for most domestic hot water return lines. In certain applications where large circuits are used with high flow rates, the thermostatic balancing valve may be manifolded together to achieve the desired flow.
With routine maintenance, a thermostatic balancing valve is expected to operate for 15+ years. If maintenance is required, then the preassembled cartridge containing the control components can be removed from the valve body for checking, cleaning or replacement if required.
The 116 series thermostatic balancing valves will never shutoff 100% as some flow is required across the temperature sensor for effective operation. If there is a concern that all valves in the system close to a point where there is insufficient flow returning to the pump, then it is possible to utilise either a manual balancing valve, or a differential bypass valve for example on the index circuit in order to ensure the minimum flow achieved.
All Valve Industries has supplied thousands of thermostatic balancing valves to the market, both for new builds and retrofit installations. Please call us for some sample project references.
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