Receiver Dryer: Testing and Inspection

A restriction inside the receiver-dehydrator will result in high head pressures if the restriction is on the inlet side of the unit. A restriction at the outlet side will cause low head pressures and little or no cooling. An exceedingly cold receiver-dehydrator may be restricted.
If the system has been in service for a considerable amount of time, the desicant element may have lost its moisture absorbing ability. This condition is indicated by the constant presence of small bubbles in the sight glass if equipped and a wide difference in temperature between the inlet and outlet receiver-dehydrator lines.