Integrated bypass developed by Hydac SA

Time schedule What is an integrated bypass Why this development How do the IBP & IBT valves function Paolo 2 Integrated bypass

What is an integrated bypass Paolo 3 Integrated bypass Hydac’s integrated bypass is a standard bypass mounted inside a special radiator expressly designed for this. A bypass is necessary to limit the inlet pressure and to help the rig’s startup with cold liquid.

Why ?...only advantages ! Why ?...only advantages ! TO REDUCE : Problems Space Cost With easy maintenance >> NEW and innovative Paolo 4 Integrated bypass

Even better than the standard external bypass Even better than the standard external bypass Paolo 5 Integrated bypass Standard radiator Standard radiator with external bypass 3 bar Radiator with IBP3 Radiator with integrated bypass

IBP operation Pressure drop depending IBP operation Pressure drop depending The IBP valve is closed if the pressure drop in the element is lower than the action set valve. Paolo 6 Integrated bypass When the bypass is open the liquid flows through the element and the bypass channel. The IBP valve opens if the pressure drop in the element goes over the action set valve. Pressure drop Oil flow Close valve Valve open action values set

IBP action Valve & channel pressure drop IBP action Valve & channel pressure drop Available valves : 2 bar >> IBP2 3 bar >> IBP3 Paolo 7 Integrated bypass  p opening valve action  p with valve compleatly open Tolerance ± 5 % This holds into account the spring variability action and the channel dimensions.

IBP estimated Element pressure drop IBP estimated Element pressure drop Combine the curves to obtain the element pressure drop. To do this it is only necessary to translate the valve pressure drop curve parallel to the oil flow axis until it is tangent to the pressure drop matrix. Paolo 8 Integrated bypass

IBT operation Temperature depending IBT operation Temperature depending Paolo 9 Integrated bypass The IBT valve is closed if the inlet oil temperature is above that of the action set valve (hot liquid). To have the maximal power heat exchange. The IBT valve is open if the inlet oil temperature is below that of the action set valve (cold liquid). To reduce the pressure drop consequent to the viscosity increase.

IBT action Temperature settings IBT action Temperature settings Available with closing temperatures of : 45 °C>>IBT45 50 °C >>IBT50 60 °C >>IBT60 This means that, for an IBT45 the bypass is open until 45 °C and after this it will start to close. It takes 5°C to close the valve completely (IBT45 is completely closed at 50 °C and IBT60 at 65°C) The tolerance is  3 °C Paolo 10 Integrated bypass Now we are checking for the pressure drop on the elements with open bypass (low temperature).

the valve action is the same of an IBP valve (it opens if the pressure drop in the element goes over the action set valve). IBT operation Pressure drop depending IBT operation Pressure drop depending Available valves : > 2 bar (like an IBP2) Paolo 11 Integrated bypass When the IBT valve is closed because the temperature is above the action set valve,

IBT estimation Element pressure drop IBT estimation Element pressure drop Combine the curves to obtain the same element pressure drop as for the IBP element. Paolo 12 Integrated bypass Take care of the viscosity of the liquid (declared values at 30 mm 2 /s)