42 are a pair of conduits 44 and 46 the hose 44 transmits air from the flow control device 42 to a lower part 50 of the buck 16 to allow inflation of the buck body while the buck 16 is at the dressing station 14 the conduit 46 connects the flow control device 42 with the heat exchanger 30 to transmit pressurized air to the top of the buck 16 when the buck is at the pressing station a pair of two way air cylinders 52 and 54 are connected to an upper part of the housing of the flow control device 42 and move in a reciprocating fashion within the housing 42 as will be described hereinafter a pressing plate or head 60 is heated by air which passes through the heat exchanger 30 and is delivered to the pressing plate 60 through suitable conduits not shown for clarity the steam from the pressing operation is collected and returned through a specially provided conduit 62 schematically shown in fig2 into the heat exchanger for subsequent recirculation the heat exchanger conventionally contains a steam heated coil for heating of the air supplied to the expandable buck body 16 the heated air from the heat.