BALANCING VALVES
“When properly balanced, hydronic heating systems have the potential to deliver a precise rate of heating when and where it’s needed within a building. Without proper design, and proper balancing, that potential rarely becomes reality.”
temperatures that are too low, too high, or both. Wide variations in interior temperature often lead to problems beyond the lack of comfort. When some areas of a building cannot be warmed to the desired room air temperature, issues such as frozen piping, the appearance in shrinkage cracks in wood and drywall surfaces, condensation on windows and growth of mould and mildew can occur. Wasted heating energy due to higher heat losses. Some other undesirable conditions that can result from improperly balanced systems include high flow velocities in piping components creating noise and possible erosion, excessive energy use by circulators due to overflow conditions, as well as circulators that operate at low efficiency, or circulators that operate at high differential pressure which increases the potential for thrust damage of bushings or bearings. FINDING A SOLUTION To overcome these problems, it is normal practice to install various balancing devices. These include static balancing valves and dynamic balancing valves.
The designer of any system calculates the flow rate required to each terminal unit and selects the type and size of the balancing valve to control the flow based on the type of pumping system utilised (constant speed or variable speed). Variable speed pumps are more common today, due to their ability to vary the flow rate to meet demand. Thereby reducing flow rates around the system, reducing system heat losses, reducing pumping costs, thereby increasing system delta-T and system efficiency. Static balancing valves or manual balancing valves are conventional valves suitable for use in constant flow rate circuits frequently in conjunction with 3-port valves or downstream of the differential pressure control valves in variable volume systems. Dynamic balancing valves include Constant Flow Regulators, Differential Pressure Control Valves (DPCVs) and Pressure Independent Control Valves (PICVs). Constant Flow Regulators are modern automatic devices that respond to changes in differential pressure to maintain the design flow rate of the
internal flow regulating cartridge. DPCVs are adjustable and respond to changes in differential pressure automatically, adjusting to maintain a stable differential pressure between the capillary insertion point and the valve body. PICVs control differential pressure across themselves, allowing a stable flow rate to be set on the valve regardless of any differential pressure changes upstream of the valve. The addition of a control head, ON/OFF or modulating, allows the valve to become the terminal unit control valve. Altecnic has an extensive range of balancing valves for both domestic and commercial applications with many features and benefits, full information for these can be found on our website. Pictured is the Altecnic 130 Series manual balancing valve - a fixed orifice double regulating valve (FODRV) which uses a venturi to measure the flow of liquid passing through the valve. The venturi is located upstream of the double regulating valve which provides stable flow measurement during flow regulation. This also makes the valve quieter as the flow passes through the valve.
For more information, contact Chris Reilly, Country Manager for Ireland, on +353 (0)85 215 2288 or e-mail chris.reilly@altecnic.co.uk or Gary Swann, Northern Ireland Sales Manager on +44 (0)7760 596727 or e-mail gary.swann@altecnic.co.uk or visit the website at www.altecnic.co.uk
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