Pump Seal Wash Kit — Sales and Instrument Support

Seal wash kit - also called piston rinse or seal rinse - for HPLC pump heads. The kit provides the tubing, fittings and wash seals that let a weak alcohol/water mixture circulate behind the high-pressure piston seal, continuously washing the piston surface where it leaves the seal.

Its whole purpose is to dissolve buffer salt before it can crystallise. Salt crystals on the piston are the main cause of both scored pistons and short seal life, so a working seal wash is the cheapest life extension available on a pump that runs buffered methods.

Getting the benefit from it

• A typical wash solution is around 10 to 20 percent isopropanol or methanol in water; the manual for the pump is the authority on the exact mix.
• The wash reservoir needs changing regularly - it is dilute aqueous alcohol at room temperature and it does grow microbes, which then block the wash lines.
• The lines must actually be flowing. A seal wash that has been left dry, blocked or disconnected gives no warning of its own; the first sign is a seal failing far earlier than its schedule.
• Tubing that has gone stiff or discoloured should be replaced with the seals rather than reused.