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5.6.1 Purge valve needle replacement
Note: Before removing the needle, either remove the inlet tube or place the solvent
reservoir in a lower position than the pump in order to prevent spilling or
leakage of the solvent.
Refer to Fig. 5.22 and replace the needle. After the needle has been replaced,
perform the pressure test described in Section 3.1.3 and check the purge valve for
leaks (See Fig. 2.2). If the test reveals a leak, see Section 2.4.3, which describes
procedures for dealing with leaks from the purge valve.
The needle is secured to the knob by an Allen screw.
Inlet tube
Needle
Knob
Guide
Figure 5.22 Purge Valve Needle Replacement
5.6.2 Purge valve packing replacement
First, refer to Fig. 5.22 to remove the needle, then refer to Fig. 5.23 to replace the
packing. Be sure the needle is inserted into the guide when the guide screw is being
tightened (See Fig. 2.5). Tightening the guide without the needle inserted might
compress the packing excessively, leaving too little space to allow the needle to be
inserted.