Replacing The Check Valves - Thermo Scientific EASY-nLC 1200 Troubleshooting And Maintenance Manual

5
Routine Maintenance

Replacing the Check Valves

Replacing the Check Valves
82 Troubleshooting & Maintenance Guide
If a check valve is not functioning, replace it.
Replacing a check valve requires the following tools, materials, and replacement parts.
Tools
• 9/16 in. open-ended wrench
• #2 Phillips head screwdriver
CAUTION Wear powder-free gloves and safety glasses when handling parts of the LC system
that come into contact with solvents.
❖ To replace a check valve
1. Close down the EASY-nLC system, and turn off the power to the instrument (see
"Closing Down the EASY-nLC Instrument"
2. Using a #2 Phillips head screwdriver, make a quarter turn to loosen the three captive
screws that secure the right side panel to the instrument housing. Then remove the panel.
3. Do the following:
• For a solvent-side check valve, remove the solvent inlet line from the check valve, and
then terminate the solvent line with a plug.
• For a waste-side check valve, remove the waste line from the check valve.
CAUTION To prevent solvent from siphoning out of the solvent bottle on top of
the instrument and onto system components, use a plug to terminate a solvent
inlet line when you disconnect it from the solvent-side check valve.
The pump PCB is easily damaged by contact with solvents.
4. Do one of the following:
• For a solvent-side check valve, use a 9/16 in. open-ended wrench to loosen the valve
from the check valve assembly.
• For the waste-side check valve, remove the check valve by turning it counterclockwise
with your fingers.
5. Screw the new check valve onto the check valve assembly. Slightly tighten the solvent-side
check valve to the assembly using a 9/16 in. open-ended wrench.
Parts and materials
• Powder-free safety gloves
• Solvent-side check valve, P/N LC233
• Waste-side check valve, P/N LC234
on page 22).
Thermo Scientific