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STB Strata™

The STB Strata™ System is a two-stage air cleaner that ejects pre-cleaned dust through an aspirated muffler or exhaust ejector. It protects heavy-duty engines in heavy dust conditions.
The STB Strata™ System protects heavy-duty engines (like this one operating in severe dust conditions) with two-stage filtration and the convenience of aspirated dust ejection.


  • Allows 29.7 to 39.6 m3/min / 1050 to 1400 cfm airflow throughput per air cleaner
  • For severe dust conditions, usually off-road applications: crawler tractors, scrapers, loaders, large agricultural tractors
  • Horizontal installation


  • Sure sealing system
  • Durable construction withstands extreme conditions
  • Easy to service
  • Extended Service and Donaldson Blue™ high efficiency filters are available

Air Cleaner Features

  • Air cleaner and pre-cleaner in one package (exhaust ejector, scavenge hose and clamps sold separately)
  • Pre-cleaned dust is ejected with the engine exhaust through an aspirated muffler or exhaust ejector
  • Airflow pattern “B” air through the pre-cleaner, out the end of the air cleaner
  • Perfect for:
    • Turbocharged engines
    • Intercooled engines
    • Naturally aspirated engines
  • Fitting for filter service indicator on all models
  • Finished in corrosion-resistant paint
  • Weight: 35.4 kg / 78 lb

Filter Features

Replacement filter choices include extended service filter, Donaldson Blue™ high efficiency filter for restriction maintenance, or a standard life filter for scheduled maintenance.

  • Safety filter on all models provide continuous protection during primary filter change out
This servicing information is provided as a best practices guide. It is not intended to replace or supersede the service instructions supplied by your engine or vehicle manufacturer.
  1. Check the Restriction
    Replace the filter only when the restriction level has reached the maximum recommended by the engine or equipment manufacturer.

  2. Empty the Dust Cup and Check the Vacuator™ Valves
    Switch off the engine. The dust cup should be emptied when 2/3 full. Frequency of dust cup service varies with the dust severity. On dust cups with a Vacuator Valve, dust cup service is minimal. Just check the Vacuator Valve to see that it is not inverted, damaged or plugged. If it is damaged or missing, replace it immediately. Visually inspect gasket between dust cup and lower body — if worn or damaged, replace.

  3. Inspect the Donaclone™ Pre-Cleaning Tubes
    With the dust cup removed, check the tubes. Generally, the tubes are self-cleaning and need no service, but under unusual circumstances, plugging can occur. A visual inspection is usually adequate. If the tubes carry light dust, remove it with a stiff brush. If plugging with fibrous material is evident, remove the Strata™ or Donaclone section. Clean it with compressed air or water no hotter than 72° C / 160° F. Any time the Donaclone tube lower body is removed, the body gaskets should be replaced. When reinstalling the dust cup, be sure it seals 360° around the air cleaner body.

  4. Remove the Primary Filter and Visually Inspect the Safety Filter
    Unlatch the service cover to access the filters. Loosen the wing nut and remove the primary filter. The wing nut on the old filter should be held in place with a clip. Visually inspect the safety filter but do not remove the filter unless it is damaged or due for change-out. The safety filter should be replaced every three primary filter changes. 

  5. Always Clean the Inside of the Filter Housing
    Dirt left in the air cleaner housing can be harmful for your engine. Starting with the sealing surfaces, use a clean, damp cloth to wipe the inside surfaces clean. An improper gasket seal is one of the most common causes of engine contamination, so make sure that all hardened dirt ridges are completely removed.

  6. Install the New Filters
    The safety filter should be replaced every three primary filter changes or as denoted by the SafetySignal™ service indicator. When replacing the safety filter, install the new filter immediately or cover the inlet with a cloth so that dirt is not ingested. Before installing the new filters, inspect them for shipping damage and gasket integrity. If a filter is damaged, do not install it. If the safety filter is being replaced, and a SafetySignal is used, secure it in place with a cotter (split) pin. Secure the primary filter in place with the wing nut (hand tighten) using a new gasket washer. Use a new wing nut clip and reset the filter service indicator.

  7. Inspect Air Cleaner System
    Finally, inspect and tighten all air cleaner system connections. If there are holes or damage, replace immediately. Inspect all air ducting for worn spots or damage. Annual replacement of air cleaner system gaskets is recommended. 

Donaldson SRG, STG, STB Air Cleaners

Find out more about Donaldson's original mining air cleaners models SRG, STG, STB axial seal Air Cleaners. Find out how to properly service these units see how our Dust Dumpa dust cup kit can save valuable service time.