Thermo Scientific Accela 1250, Hardware Manual

Page: 121 / 170

5
Maintenance
Replacing the Primary Piston Seals
Thermo Scientific Accela 600 and 1250 Pump Hardware Manual 97
Replacing the Primary Piston Seals
Replace the two primary piston seals as part of a regularly scheduled, preventive
maintenance routine or if you detect a leak from the LDA. Thermo Fisher Scientific
recommends replacing the primary piston seals every 6 to 12 months, depending on your
pump usage.
The primary piston seals for the Accela pumps are made of GFP and have a spring made of
Hastelloy™, an alloy of stainless steel (see
Figure 95 ).
Figure 95. Primary piston seal with a view of the spring
 To replace the primary piston seals
1. Remove the LDA from the pump (see “Removing the LDA from the Pump” on page 79 ).
2. Disassemble the LDA (see “Disassembling the LDA” on page 85 ).
3. Remove the piston from the holding hook and guide bushing (see Figure 96 ).
Figure 96. Piston, holding hook, and guide bushing assembly
spring
Piston
Guide bushing
Holding hook