Gilson 333 - Check Valves

Check Valves
The check valves are supplied as cartridges: one for the inlet connector and one for the outlet
connector. The two check valves, inlet and outlet, should be cleaned periodically to ensure
reliable flow rates. Reliable flow rates will be achieved only if the check valves are kept in good
operating condition by proper care and maintenance.
NOTE
Check valve cartridges are identical for H3 pump heads, but the connectors for inlets and outlets
are dierent for each. Because the dimensions of the threaded parts of the connectors are dierent,
neither the connectors nor the cartridges are interchangeable.
The check valves must not be disassembled into sub-components. No check valve
sub-component is available from Gilson.
Cleaning a Check Valve
This procedure is carried out with the check valves installed:
1. Open the purge valve on the PPMM to the drain position. Make sure the purge line is
connected and directed to an appropriate waste receptacle.
2. Pump isopropanol (provided the current solvent and isopropanol are miscible).
CAUTION
To prevent injury, observe good laboratory practices when handling solvents. Know
the physical and chemical properties. Refer to the Material Safety Data Sheets for the
solvents used.
3. When the pump head is full of isopropanol, stop the flow for at least 15 minutes, to dissolve
any sticky deposits.
4. Reconnect the previous solvent and then pump the isopropanol to waste.
5. Check the flow rate. If the flow rate is still low, remove the check valve and then clean the
check valve by blowing compressed air though it. If the flow rate is still low, replace the
check valve.
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333/334 HPLC PUMPS | USER’S GUIDE
CHECK VALVES