Aircraft Appliances has manufactured a Gas Turbine Air Start Filter for the DDG 51 class ships. There are 3 units per ship and they are manufactured out of 70/30 CuNi and designed to flow 3.25 LBS/SEC @ 150F @ 75PSIG and 2.67 LBS/SEC @ 425F @ 75 PSIG. These units use a replaceable filter element.