Injection System; Injection Mechanics - Waters ACQUITY UPLC Overview And Maintenance Manual

1.4 Injection system

The injection flow path includes the assemblies required to aspirate a sample and deliver it to the
column. The process involves the needle, optional extension loop, sample syringe and syringe
valve, injection valve, and injection/wash port.

1.5 Injection mechanics

During an injection, this five-step sequence takes place:
1. The needle moves to the sample vial and aspirates sample from it.
2. The needle carriage inserts the needle into the injection/wash port.
Note:
The entire injection port assembly rests on a spring and is guided inside a metal
housing.
3. As the needle is inserted into the injection/wash port, it presses against the seat and forms
a high-pressure seal.
4. The injection valve turns to start the injection.
5. The wash pump washes the outside of the needle during the injection.
Figure 1–8: Cross-view of injection needle and seal
9
8
Overflow cup
Force applied through the needle carriage
Needle motion
1
10
NEEDLE
7
June 11, 2019, 715005051 Rev. D
2
3
4
5
6
Page 18