As a general rule of thumb, HYDAC recommends that the clean element pressure drop be no more than: 10-15% (at average flowrate) of the clogging indicator trip setting for lubrication systems, 20-25% for industrial applications, and 20-30% for mobile applications. Be sure to also check the pressure drop at cold start temperatures and maximum flowrates. If at these conditions the pressure drop is greater than 50%, then the next larger size should be selected. Note, make sure that the filter port size is large enough to handle the desired flowrate.