Fully sealed down the hole hammer

A down the hole drilling assembly comprising:

• a drill bit having an elongated shank and a drilling end;
• a driver sub at least partially arranged around the drill bit;
• a flushing passage defined by an outer surface of the shank and an inner surface of the driver sub;
• at least one flushing channel formed in the drill bit, wherein the at least one flushing channel includes an inlet port fluidly connecting the flushing passage and the at least one flushing channel and an outlet port arranged at the drilling end;
• and
• a sealing element arranged in the flushing passage and extending radially from the outer surface of the shank to the inner surface of the driver sub, wherein the flushing passage and the at least one flushing channel are configured to allow a flow of fluid from the flushing passage to the at least one flushing channel in a flow direction (F) of the fluid, wherein the sealing element is positioned above the inlet port of the at least one flushing channel along the flow direction;
• and wherein the sealing element is configured to be forced to deform to an open configuration by fluid flowing in the flow direction thereby allowing fluid flow in the flow direction and to subsequently close to prevent a flow of fluid in a direction opposite to the flow direction.