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Replacing the in-line filter cartridge on the primary check valve
Replacing the in-line filter cartridge on the primary check valve
Topic LCI-USG-0161, Last Updated 05/19/2025
Users or Waters field service personnel can replace the in-line filter cartridge on the pump primary check valve.
Warning: Observe Good Laboratory Practice (GLP) at all times, particularly when working with hazardous materials. Consult the Safety Data Sheets regarding the solvents you use. Additionally, consult the safety representative for your organization regarding its protocols for handling such materials.
Note: To avoid contaminating system components, wear clean, chemical-resistant, powder-free gloves when performing this procedure.
Required tools and materials
Chemical-resistant, powder-free gloves
Replacement in-line filter cartridge
To replace the in-line filter cartridge on the primary check valve:
Flush the pump with nonhazardous solvent that is miscible with the present mobile phase.
Power-off the system to guarantee that the GPV valves are closed and to avoid any siphoning. See Powering-off the system.
Open the pump compartment door.
Hold the PEEK inlet filter fitting while unscrewing and remove the PEEK inlet filter nut from the fitting.
Figure 1: Unscrewing the PEEK inlet filter nut and PEEK inlet filter fitting
PEEK inlet filter fitting
PEEK inlet filter nut
Figure 2: Removing the PEEK inlet filter nut from the PEEK inlet filter fitting
PEEK inlet filter fitting
PEEK inlet filter nut
Slide the PEEK inlet filter nut down the tube and disengage the filter from the PEEK inlet filter fitting.
Figure 3: Sliding the PEEK inlet filter nut down the tube
Slide the metal locking ring downward off the in-line filter cartridge and slide the cartridge off the tube.
Inspect the filter cartridge to determine whether it is constructed of stainless steel or titanium (Ti), and ensure that you have the correct replacement cartridge. No marking indicates a filter cartridge constructed of stainless steel, and "Ti" indicates a filter cartridge constructed of titanium.
Slide the metal locking ring onto the tube, ensuring that the tapered inside diameter is facing up.
Figure 5: Sliding metal locking ring on tube
Metal locking ring
Non-tapered inside diameter of metal locking ring facing toward PEEK inlet filter nut
Tube
PEEK inlet filter nut
Unpack the new in-line filter cartridge.
Place the new in-line filter cartridge onto the end of the tube.
Figure 6: Placing in-line filter cartridge onto end of tube
In-line filter cartridge
Tube
Metal locking ring
PEEK inlet filter nut
Verify that the cartridge is bottomed out in the tube, and then slide the metal locking ring onto the boss on the bottom of the in-line filter cartridge while making sure the tube stays bottomed out.
Insert the in-line filter cartridge with tubing into the PEEK inlet filter fitting, finger-tighten the PEEK inlet filter nut until it bottoms out, and then tighten it 1/4-turn.
Figure 7: Installing the PEEK inlet filter nut on the PEEK inlet filter fitting
To avoid risk of personal injury and to prevent damage to laboratory equipment, always operate your Waters products in accordance with the applicable operational and safety information, your organization’s standard operating procedures, and local regulations.
Refer to the English version of this page for the latest information.
Pump maintenance procedures
