to high torque it may not be serviceable by hand and could require breakout equipment by ensuring that the hammer union 22 is serviceable by hand the hammer union 22 can be opened for inspection if there is ever a problem with the wiper plug also after cementing the entire cement head can be removed from the casing connection 48 and serviced at a later time without requiring further time or breakout equipment during critical time sensitive cementing jobs in the case of slant rig operations it is often difficult to thread a complete cement head with a top drive onto a well casing and without damaging the threads in the present invention the bottom sub 30 is installed to the casing in the slips and then torqued to predetermined settings next the top sub 2 is installed to the top drive by lowering the top drive with the top sub 2 attached until the female union 24 end meets the male union 26 end in this arrangement there is less chance of damage to critical threaded materials the hammer union 22 is tightened by hand and then by hammer until the torque block slots are lined up torque blocks 28 preferably two of them 180 u00b0 apart are then installed.