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Braukmann Automatic bypass and differential pressure valve with differential pressure indicator, DU146

Braukmann Automatic bypass and differential pressure valve with differential pressure indicator, DU146

The automatic bypass and differential pressure valve controls water flow in the heating circuit according to the water...

Product Description

The automatic bypass and differential pressure valve controls water flow in the heating circuit according to the water pressure across it and is used to maintain a minimum flow rate through the boiler and to limit circulation pressure when other water paths are closed. A bypass circuit must be installed if the Boiler manufacturer requires one, or specifies that a minimum flow rate has to be maintained whilst the Boiler is firing. The use of automatic bypass valves becomes particularly important when heating systems include large numbers of thermostatic radiator valves (TRVs) - whilst the TRVs are open the automatic bypass valve remains closed, however, as the TRVs start to close, the automatic bypass valve starts to open maintaining the required water flow through the boiler. Using an automatic bypass valve is also likely to reduce noise in systems caused by excess water velocities. It also helps to reduce the corrosion caused by flue gas condensation as the boiler return temperature is raised. 

Technical Properties

Medium type water or water-glycol mixture according to VDI 2035
Port connection internal threads
Maximum operating pressure 3 bar
Differential pressure setpoint range 0,05 ... 0,5 bar
Max. media temperature 110 oC
Materials

Unpolished brass housing, brass fittings and valve disc, High-grade synthetic material spring bonnet, high-temperature resistant synthetic material display tube, stainless steel spring, EPDM seals

Additional Descriptions
  • Maintain minimum flow through a boiler
  • Minimizes flow noise
  • Hinders boiler corrosion
  • Differential pressure finely adjustable using the indicator scale integrated in metal housing 
  • Presetting accessible directly 
  • Setting value is in meters water column
  • No external controls required
pH-range 8 ... 9,5
Differential pressure setpoint fixed 0,2 bar

Products

Product Type Product description
Port diameter
Products

DU146-3/4A
For installations up to approx. 70 kW (60.000 kcal/h) 3/4 inch

DU146-11/4A
For installations up to approx. 232 kW (200.000 kcal/h) 1 1/4 inch

Accessories and replacement parts

Spare parts

Image Description Product Type Downloads
Complete indicator tube For DU146 differential pressure and bypass valve comprising: Indicator tube, spring, indicator piston and 5 O-rings DU146AH-A  
Valve insert, 3/4" 0900311  
Valve insert, 1 1/4" 0900312