The Maintenance of HPLC’s Plunger Rod and Plunger Piston Sealing Ring
Plunger piston sealing rings are divided into normal phase and reversed phase. The reversed-phase sealing ring is with the color of black and made of graphite. Normal phase sealing ring is orange and made of polyethylene, and it is more suitable to the normal phase solvent. Generally, the liquid chromatograph is equipped with a reversed-phase sealing ring. When normal phase is applied, the sealing ring should be changed into a normal phase.
HPLC plunger piston sealing ring is covered on the plunger rod and used for isolating the pump from the outside. When working, the ring rubs with the rod frequently, and it will be frayed after a period of time. As a result, the plunger piston sealing ring should be changed regularly to ensure of airtightness of the system.
You should check if there is a scratch on the plunger rod when changing the sealing ring. Because scratch will lead to slight leakage and reduce the service life of the sealing ring.
Saline solution has a great influence on the service life of sealing ring. If the saline solution is used as the mobile phase system, you should pay attention to the wash of solution channel. Moreover, the saline solution cannot be kept in the pump after HPLC stops working.