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5.4.3 Post-replacement verification
Refer to sections 3.1.2 and 3.1.3 and perform the pressure test. Verify that there are
no leaks from the check valve assembly (See Fig. 2.2). If the test reveals a leak, see
Section 2.4.2, which describes procedures for dealing with leaks from the check
valve assembly.
5.5 Replacement of the plunger washing mechanism diaphragm
5.5.1 Preparations for diaphragm replacement
Replace the solvent inside the pump with one of the following solvents (See Section
4.2):
y
Methanol
y
Water
Since this operation involves the disassembly of the pump, solvent or liquid
remaining inside the pump will unavoidably come into contact with fingers and hands.
In addition, a leak may develop during the pressure test. Therefore, a solvent that is
relatively harmless to both humans and the instrument must be selected for use
during diaphragm replacement. If organic solvents are currently being used, replace
these solvents with methanol. If a buffer solution or other solution containing salts is
being used, replace this solution with water.
WARNING
: Chloroform and acetonitrile are hazardous to the human body and
should not be used for the pressure test.
CAUTION: Since, salts in buffers may precipitate, causing poor instrument
performance, do not use buffers for the pressure test.
Note: Since water tends to leave air bubbles in the pump head, be sure that any
water used for the pressure test has been sufficiently degassed.