Reducing pump energy in a water distribution system is a challenge for any designer. Increasing the pipe size and reducing the pressure drop/metre, does reduce the amount of pump energy, especially if the system is variable volume. Increasing the pipe sizes has an adverse effect on the conventional flow measuring Orifices, which results in a smaller design signal, typically below 1 kPa or no signal at all. Having, very low or no design signals during the commissioning of the system, makes it impossible to build a picture of flow distribution, critical for fault finding.
The problem of a smaller design signal in larger pipe work is accommodated with the selection of a smaller orifice in an appropriate size body. This could mean one or even two sizes less than the pipework sized by the designer. A reduction in pipe size means a lower valve cost, but an increase pipework components and associated labour is required to make the alterations. Plus the installed Orifice plate requires 5 diameters of same size straight pipework installed upstream and 3 diameters downstream. Apart from the space required
Pettinaroli have developed an interchangeable Venturi system that works for conventional and low loss pipework pressure drops. Using a smaller diameter Venturi that has been manufactured to fit in a larger size body keeps.
Evolution of Pipework In a constantly progressing society, the industry has had to evolve alongside it to meet the ever changing requirements. It’s had to look for better ways to design its pipework to make sure that systems can always be optimised and needs are...
Is proportional balancing still the best approach to commissioning variable volume systems? Martin Lowe, Director at MLowe Consulting, suggests a faster and more practical method. iVariable volume fan coil and chilled beam systems continue to increase in popularity...