These are the basic types of oil transfer pump used for pumping oil to an appliance or appliance's where the oil cannot be supplied to the appliances under gravity. - They are fitted with a low pressure spring but still need to be used in conjunction with a pressure reducing valve fitted on the 'T' off to each appliance. - On a ringmain system - i.e. a return to the tank, a back pressure relief valve is fitted on the main pipe run after the last appliance 'take off'. - If pump is run 24/7 this will greatly reduce the life of the pumpset. - All models supplied with filter & on a drip tray.