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DPK350 Cartridge

DPK350 duplex filter assemblies allow continuous filtration during filter servicing to avoid machine shutdown. The DPK350 duplex design combines lighter weight aluminum heads with durable steel bowls for a high-performance assembly. Choose between optional features such as no by-pass, by-pass valve, visual indicators or combination electrical/visual indicators for a customized assembly that best fits the needs of your specific application.


  • In-Plant Systems
  • Lube Oil Systems
  • Process Fluids


  • Allows continuous filtration during filter servicing
  • Highly configurable to fit your application requirements
  • Featuring our high-performance DT filters with multiple efficiency options – allowing you to achieve the performance you need for most any application


  • Strong, durable anodized aluminum alloy head and steel housing
  • Deep pleat filters for higher dirt holding capacity
  • Service indicator options – electrical/visual or visual options
  • Available with no bypass or with bypass valves for design flexibility
  • Automatic bleed-over valve
  • Six grades of media 
  • Viton® seals are used on high-performance DT filters
  • Working pressure to: 24 bar / 350 psi 
  • Rated static burst to: 48 bar / 700 psi
  • Flow range to: 379 lpm / 100 gpm
  • Porting size options: 
    • 1-1/2" SAE 4-Bolt Flange Code 61
  • Bypass ratings of:
    • 3.5 bar / 50 psi 
    • No bypass

Available Media Types

  • Donaldson exclusive DT Synteq™ – synthetic fiber media for greater filtration efficiency and higher dust-holding capacity
  • High collapse options


Viton® is a registered trademark of E. I. DuPont de Nemours and Company. 


The following are recommended practices for hydraulic filter servicing and handling. These steps are universal to many hydraulic systems. This servicing information is provided as a best practices guide. Donaldson recommends that you follow the filter service instructions supplied by your original equipment manufacturer. These recommended practices are not intended to replace or supersede the service instructions supplied by your equipment or vehicle manufacturer.
  1. Check the filter service indicator
    Check to see that the OEM specified service interval has been reached or that the service indicator shows that the filter is due for servicing.

  2. Turn system off and release pressure
    Ensure that the hydraulic system is turned off.
    Check that there is no pressure present.

  3. Use oil drain port to remove oil from the housing 

  4. Unscrew the cover, inspect seals for any damage

  5. Remove the used filter and gasket, if applicable
    Properly dispose of the cartridge according to local regulations.

  6. Clean housing to cover seal area

  7. Inspect the new filter cartridge for damage
    Check the new filter you will be installing for any shipping and handling damage. Never install a damaged filter.

  8. Lubricate element seals. Install new cartridge
    Lubricate the o-rings, gaskets, housing seals and threads with clean system oil. Install filter into the housing.

  9. Lubricate cover seals and install
    Fit the housing to the filter head as instructions on the housing.

  10. Hand tighten cover to housing

  11. Bleed the system and check for leaks

Donaldson Hydraulic Filtration Overview

Donaldson provides filters and contamination control products to protect hydraulic components -- in the factory and on heavy-duty equipment. This module provides an overview of hydraulic systems and the advantages of Donaldson hydraulic filters.

Donaldson Hydraulic Filter Servicing

Donaldson provides best practices and recommended steps for hydraulic filter servicing. By following these simple steps, discover how you can reduce maintenance costs and extend the life of your hydraulic system