Replacing The Purge Screw (Loading Pump) - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

UltiMate 3000 Series:
NCS-3500RS and NCP-3200RS

7.10 Replacing the Purge Screw (Loading Pump)

Relevant only for the loading pump
Description
Purge screw (with integrated cap seal) for loading pump
Replace the purge screw when
• Leakage is observed around the valve screw when the valve is open.
• Leakage is observed on the purge outlet when the valve is closed.
1. If necessary, purge the pump to remove harmful solvents.
2. Set the pump flow rate to 0. Wait until the system pressure is down to zero.
3. Remove the purge screw from the purge unit. Turn the screw counterclockwise all the
way and then pull it straight off the purge unit.
4. Before installing the replacement purge screw, clean the hole in the purge unit with a
cleaning swab (part no. 6040.0006).
5. Hold the replacement purge screw carefully. You should not hold the screw by the seal
end to avoid scratching the seals. These scratches will prevent proper seal and allow
leakage.
Integrated cap seal
6. Insert the purge screw into the purge unit, turn the screw clockwise, and tighten
fingertight. Tighten with your hand only (use no tool). Overtightening may destroy the
purge valve seals.
7. Resume operation and check whether liquid leaves the purge outlet. If it does, the
screw may not be tightened enough. Tighten the screw a little more.
Page 210
Fig. 82: Purge screw
Part No.
6040.2035
Ring seal
Operating Instructions