to the field vanes 50 a p define a plurality of passageways 52 a p in the preferred embodiment 16 passageways are shown however a larger number or a smaller number of passageways can be used depending on the fluid matrix pressure pipe size and other operational parameters the side wall 44 of the body 12 together with the cap 36 and the bottom 42 direct fluid flow as it exits the passageways 52 a p the guide vanes have a generally heart shaped outline each passageway 52 has a beginning 58 and an ending 60 the beginning 58 in fluid communication with the inlet zone 48 and the ending 60 is in fluid communication with the transition zone 32 in the preferred embodiment the area of each beginning 58 has a cross sectional area that is about twice as large as the cross sectional area of the end 60 the width of each passageway 52 at the beginning 58 is preferably equal to the circumference of the inlet zone 48 divided by the number of passageways 52 the area of the beginning 58 and the end 60 of each passageway 52 may be modified during manufacture depending on the fluid matrix pressure pipe size and other operational parameters the ends 60 of each passageway 52 a p may have different widths in order to achieve the optimum velocity profile described in fig1 below the taper of the discharge nozzle 34 is important to reduce turbulence of the fluid as it passes from the.