Waters 1500-Series, Operator'S Manual

Page: 114 / 188

5-6 Maintaining the HPLC Pump
Replacing and cleaning plunger seals and plungers
This section describes these procedures:
• Removing and installing plunger seals for replacement
• Removing and installing plungers for cleaning and replacement
The plungers in a 1500-series pump are ultrasmooth, chemically inert
sapphire rods. Salt crystals that precipitate from the eluent can form on the
plunger and cause wear on the plunger seals and on the plunger itself. The
result is a slow leak and a very slight cyclic pressure fluctuation, with a
possible increase in retention time.
For continued high-performance operation of the pump, perform the following
maintenance tasks:
• Replace the plunger seals and bearings twice yearly, or as needed
• Replace the plunger twice yearly, or as needed
• Clean and inspect the plunger every six months (or sooner if using
abrasive eluents)
Preparing for plunger seal replacement
Required materials
• Open-end wrench, 5/16-inch (startup kit)
• Allen wrench, 5/32-inch (startup kit)
• Adjustable wrench (startup kit)
• Priming syringe (startup kit)
• Fitting plug (startup kit)
• Replacement seal kit, plunger seal insertion tool, and seal extraction
tool (startup kit)
• HPLC-grade methanol
Removing the pump head
To gain access to a plunger seal, you must first remove the pump head.
Before starting this procedure, move the eluent reservoir below the pump
head level to prevent gravity flow of the eluent.