Waters 1500-Series, Operator'S Manual

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Replacing check valves 5-19
6. Carefully slide the pump head assembly off the pump (see page 5-6 ).
7. Hold the pump head upside-down in one hand with the outlet check
valve housing facing downward. Remove the entire outlet check valve
housing and replace it with a new one.
8. Finger-tighten the new outlet check valve housing into the pump head.
9. Turn the pump head over and carefully slide the pump head over the
plunger and onto the pump.
10. Holding the pump head securely against the pump, reinstall the two
screws, alternately tightening the screws to secure the pump head to the
pump. Do not overtighten.
11. Tighten the outlet check valve housing with the adjustable wrench.
12. Reinstall the outlet tubing and inlet tubing assemblies.
Tip:
Use the 5/16-inch open-end wrench to tighten the compression
screw while holding the housing with the adjustable wrench.
13. Prime the pump as described in Chapter 4 . Check for leaks.
Replacing 1525µ check valves
This section describes how to replace inlet, outlet, and restrictor tee check
valves for the 1525µ pump. These check valves employ a cartridge assembly
that you install in the check valve housing.
Replacing the 1525µ inlet check valve
To replace the inlet check valve:
1. Purge the pump with methanol (see Chapter 4 ). If methanol is not
miscible with your current eluent, use an intermediate eluent.
Caution:
Pull the pump head off straight to avoid breaking the
plunger.
Caution:
Ensure that the pump head is straight and the indicator
rod is properly aligned with the pump head to avoid damaging the
plunger.