The pump outlet assembly should have a low pressure gauge and for pump insurance,,, a pressure relief valve (I prefer an adjustable type that I usually set at 15psi). PRV protects the pump; the most expensive part of the whole system. Air gauge allows you to trouble shoot air flow problems and the PRV is insurance for the pump when there is an air blockage; extra important in freezing temps. When trouble occurs in the aeration system, the 1st question I ask is what is the reading on the air gauge. For rotary vanes, they do not tolerate psi over 30psi and then the vanes snap.
