Instruction Manual

36 Operation
The type of needle used also has an effect on needle movement. Threaded needles provide the best
support as they provide a full 360° of contact with the threads in the Luer lock ring.
Square needles with flanges (square upper edge) offer less support and can move at the unsupported
points on the flange (see Figure 3-25). Square needles offer support only at the corners, where the flange
touches the Luer lock ring. When installed, these needles should be oriented to provide support opposite
to the force generated by the stopcock movement (see Figure 3-26 and Figure 3-28).
" NOTE DO NOT flip the stopcock lever (yellow) before you place the needle into the stopcock
or you will compress the Luer lock ring and will not be able to thread the needle hub far
enough into the stopcock. As a result, less support will be available to the stopcock
taper. The tighter the two tapers (pumping chamber and stopcock) lock together, the
better the support provided tot he needle hub when you flip the stopcock lever. When
you flip the stopcock lever, the entire assembly of the needle hub and Luer lock ring is
compressed, providing additional support to the needle (see Figure 3-24).
Figure 3-25 Needles and Associated Upper Lips
Flat flange of
needle lip
Needle with
square lip
Needle with round lip
Needle with
round lip
HT-06 adapter
Flat flange of
needle lip