The picture shows the main pump head parts.

Overview of pump head parts
Figure: Overview of pump head parts

No.

Description

1

Inlet check valve, including:

1a

Valve nut

1b

Valve cartridge

2

Pump head

3

Pump head seals (2 PTFE O-ring seals)

4

Piston seals

5

Support rings

6

Seal wash bodies (pump head bushing)

7

Seal wash seals

8

Seal wash plate

9

Pistons

10

Outlet check valve, including:

10a

Valve nut

10b

Valve cartridge

11

Connectors for seal wash tubing (pluggable)

12

U-tube (capillary from working cylinder to equilibration cylinder)