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4
Maintenance
Servicing the LDA
Thermo Scientific
Surveyor MS Pump and Surveyor MS Pump Plus Hardware Manual
39
Servicing the LDA
The liquid displacement assembly (LDA) contains the parts of the pump that are subject to
routine wear and tear. These parts are the primary piston seals, the pistons, and the check
valves. Occasionally, the secondary piston seals, the check valve seal rings in the top and
bottom of the piston chambers, and the outlet seal ring might also require replacement.
Figure 29.
Components of the liquid displacement assembly (LDA)
Pressure sensor assembly
Primary piston
seal (GFP)
Seal ring, piston bore
Pressure guide bushing
Backing ring
Piston
Secondary piston seal
Check valves
LDA body
Piston guide bushing
Holding hook
Retaining clip
Actuating coil
Outlet seal ring
Outlet cartridge
Piston chambers
Check valve seal ring PTFE (5)
Compression lid
Inlet module
Proportioning valve