The bleed muffler functions much the same as the muffler on the exhaust of an automobile engine. To be effective as a sound silencer, it must decrease the exhaust gas velocity and absorb or cancel the sound waves while still allowing the free flow of exhausted gases. In the types depicted above, sound waves are cancelled by redirecting and subdividing the incoming steam exhaust into separate, smaller gas streams. The gas streams are directed towards the wall of the cylindrical chamber where they rebound to collide with opposing gas streams of equal force. With velocity greatly reduced, the steam is dispersed through openings on the cylindrical surface or on the end.
Some mufflers have baffles, packing or screening to provide a devious flow path.
In this case, the muffling action produced is at the expense of appreciable increase in exhaust back pressure. Mufflers of this type should be avoided, especially in installations where the bleeder serves a dual purpose to include a means of condensate removal. The firm should know and be able to provide the type and exhaust flow performance characteristics of mufflers in use. The model number and name of the muffler manufacturer would be an aid in determining information on the device if the firm is either unwilling or unable of to specify the performance parameters. There may be a number of ways to recognize an improperly operating muffler device.