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STG Donaclone™

The STG Donaclone™ is a powerful two-stage air cleaner that is used in a wide variety of heavy-duty mining equipment in heavy dust conditions.
This STG Donaclone, mounted on a large mining machine, is protecting the engine from harmful dirt in this severe dust environment.


  • Allows 11 to 49.8 m³/min / 390 to 1760 cfm airflow throughput per air cleaner
  • Horizontal or vertical installation
  • Off-road, high dust conditions
  • Ideal for scrapers, earth movers, graders


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

Air Cleaner Features

  • Very reliable. Only one critical filter seal.
  • Airflow throughput can be doubled by using two air cleaners
  • Two body styles (peripheral inlet and tubular inlet) to accommodate location and ducting
  • Optional inlet shroud available for peripheral style
  • When the air cleaner is mounted directly on the engine and there is clearance around it for airflow, choose the peripheral inlet style (shown on right)
  • When the air cleaner is mounted above the cab or somewhere far from the engine to get above the dust cloud, choose the tubular inlet style, which will accept ducting into the inlet
  • Built-in Donaclone pre-cleaning tubes separate up to 97% of incoming dust to the dust cup before it reaches the filter, resulting in more thorough cleaning and fewer filter changes
  • Choose the dust cup best suited to your maintenance practices. For choices see Accessories section
  • All models include a fitting for a filter service indicator

Filter Features

  • Replacement primary filter choices: Standard life filters (for scheduled maintenance) and Donaldson Blue™ high efficiency, extended service filters for servicing by restriction
  • Uses standard airflow filters
  • Safety filter on all models

How the Two-Stage STG Donaclone Works

  • Air is drawn in through the perforations in the lower part of the unit and forced down through a bank of Donaclone tubes. The Donaclone tubes spin the air so that centrifugal force causes the heavier dust particles to separate from the airstream.
  • While these particles fall into the cup at the bottom, the partially cleaned air is directed upward, into the primary filter in the upper portion of the unit for the second stage of filtration.
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.

Tip: Save Service Time — Install Dust Dumpa on Vertical STG Air Cleaners!


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.