Jesco MAGDOS LK Operating Instructions Manual

Hydraulic installationHydraulic accessories 25© Lutz-Jesco GmbH 2015Subject to technical changes.150225BA-10221-02-V03Stepper Motor-driven Diaphragm Dosing Pump MAGDOS LK Operating Instructions8.7.9 Suction pressure regulatorA suction pressure regulator may be necessary if the suction-sideinstallation of the system demonstrates a varying suction pressure orsupply pressure:n Dosing pumps that are installed above dosing tanks deliver less as thetank empties, since the suction head increases.n Dosing pumps that are installed below dosing tanks deliver less as thetank empties, since the positive delivery pressure reduces.Further problems that can occur:n Greater wear on the dosing pump, e.g. diaphragm rupture due to theeffects of heavy forces with particularly high tanks and high-densitydosing media.n Idling of the dosing tank in the case of a diaphragm rupture or pipebreakage.n Impermissibly high forces in the pump transmission that occur whendosing pumps receive the dosing medium directly from the pressureline.n Reduced performance or destruction of fittings due to cavitation withlong suction lines.Installing a suction pressure regulator is a remedy for the problemsabove. The suction pressure regulator is opened by the dosing pump‘ssuction pressure. This ensures that no dosing medium can flow if thedosing pump is not running or no vacuum can be generated following apipe fracture.Notes on assembly:n When using a large suction pressure regulator, you should provide apulsation dampener on the suction side.abecgdfhiFig. 25: Installation with a suction pressure regulatorNo. Descriptiona Main lineb Injection nozzle with shutoff valvec Pressure lined Chemical tanke MAGDOS LK dosing pumpf Wall bracketg Suction lineh Suction pressure regulatori Shutoff valveTab. 19: Designation of components