hydraulically connected to passageway 11 through a one way valve 15 in the valve and passageway assembly 4 which is shown in its closed position fig1 also shows that passageway 7 is hydraulically connected to passageway 10 through two one way valves 13 and 22 in the valve and passageway assembly 4 which are also shown in their closed position fig1 also shows that the valve and passageway assembly 4 is inserted into the end of the hollow bar 1 and is prevented from falling out of the hollow bar 1 by the seal 3 fig1 shows a sectional view of the same embodiment as shown in fig1 except that the valves 13 22 and 18 are all in their closed position preventing flow from either direction into passageway 7 valve 19 is also in its closed position preventing any backflow of fluid back past valve 19 valves 20 and 15 are in their open positions allowing fluid to flow through valve 20 into passageway 8 and through valve 15 into passageway 11 and then into the central hole 12 in the bar 1 typically fig1 shows the valve configuration during the drilling cycle where water is pumped through valve 20 and into passageway 8 and then the water pressure opens valve 15 allowing the water to.