Visually Inspecting The Pump For Piston Seal Leakage - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

7.3.1 Visually Inspecting the Pump for Piston Seal Leakage

You can inspect the pump visually for liquid leaks from the piston seals. As the pistons
move back and forth within the displacement chambers, a small quantity of mobile phase
leaks behind the primary piston seals. Before inspecting whether liquid leaks from the
piston seals, make sure that
• The rear seal wash tubing is properly connected to the rear seal wash system
(→ page 62). If the seal wash tubing is not connected properly or if the tubing is crimped
or kinked, the liquid may leak into the pump.
• After performing service procedures on the pump head, the pump head is reassembled
correctly, and the screws are tightened properly.
1. Flush the seal wash system with the seal wash solution.
2. Observe the pistons for liquid leaking out. In addition, use one or more paper strips
and cut them to approximately 5 x 2 cm. Insert the paper strip between the
displacement chambers and check whether liquid are present between the chambers.
♦ If no leak can be observed, the pump head is sealed tightly.
♦ Liquid leaking out from the displacement chambers indicates leakage from one or
both check valve cartridges. Replace the check valve cartridges and repeat the test
starting with step 1. To replace check valve cartridges, see section 7.3.4.
♦ Liquid leaking out from the guide bushings indicates leakage from one or more piston
seals. Replace the primary piston seals in the displacement chambers and repeat the
test starting with step 1. If no leakage is observed, replace the secondary piston seals
in the piston guide bushings and repeat the test starting with step 1. To replace piston
seals, see section 7.3.3.
Operating Instructions
UltiMate 3000 Series:
LPG-3400XRS Pump
Page 109