Model 20 HT / GT

The Model 20 HT/GT agitators are designed for a wide range of service in the chemical, pharmaceutical, ethanol and biofuels, water and wastewater, Flue Gas Desulfurization, power and other general process industries. The agitators feature a new, high-efficiency gearbox designed specifically for agitator service. Models are available in right angle and parallel shaft configurations to meet specific application requirements from critical chemical reactor systems to routine storage.

The new agitators combine the proven benefits of the Chemineer HT and GT agitators into a modular design package that reduces the number of replacement parts that need to be carried in inventory by the customer. The wide range of speeds available with the new agitators provides improved process control and greater application versatility. The Model 20 HT/GT agitators are designed to meet AGMA, OSHA, ANSI, IEC, DIN, EU and ATEX standards and requirements.

The Chemineer Model 20 HT/GT agitators also offer:

  • Quick and easy seal change capability that saves time and reduces maintenance costs
  • Variety of seal options for application versatility
  • High energy efficiency due to an optimized gear design and lighter weight shaft diameter requirements
  • Standard cast dry well seal eliminates lubrication oil leakage from gearbox – this design is superior to maintenance intensive, unreliable lip seals
  • Reversible rotation to meet a variety of process requirements
  • Reliable performance and long life resulting from the cast gearbox with heavy duty output shaft and bearings

Internal Shafting


  • Oversized Low Speed Shaft Diameter and short bearing span
  • Recessed low speed coupling half


  • Time proven design to handle shaft/impeller bending loads, reducing deflection and gear misalignment, thereby extending bearing and gear life
  • Simplifies installation with no requirement to install shaft up through the gearbox

Shaft Design

Both process and mechanical considerations determine shaft design. Shafts are sized to resist torsional loads and bending moments induced by hydraulic forces acting on the impeller, as well as to avoid excessive vibration due to the coincidence of critical frequencies and operating speed.



  • Double and Triple Reduction Options
  • Helical/Spiral Bevel (HT) and All Helical (GT)
  • Case Carburized Gearing


  • Double/Triple reduction decreases gear loads, lowers noise levels, and allows for non-synthetic lubrication over competitive single reduction designs
  • Highest efficient gearing available reduces energy costs
  • Reduces wear rate for 20+ year service life

Housing and Lubrication


  • Cast Gearbox
  • Dry Well Seal
  • Grease and Bath Lubrication
  • Standard R&O Oils


  • Modular designs between right angle (HT) and parallel shaft (GT)
  • Eliminates lubrication leaks which are common in commercial gearboxes with no dry well
  • Ensures vital lubrication to gears and bearings at all operating speeds, eliminating internal/external lubrication pumps
  • No Synthetic Lubrication is required saving installation and maintenance costs

Bearing Design


  • Tapered Roller Output Bearings, Grease Lubricated
  • Tapered Roller/Roller Bearings, Oil Lubricated


  • High capacity to handle shaft/impeller loads while providing long life
  • Oil lubrication provides cooler operation, longer life, and lower maintenance over grease or permanently lubricated bearings

Seal Features and Benefits


  • Drop collar shaft support during seal change
  • Swing out or spacer spool seal change designs
  • Variety of seal options from major mechanical seal vendors such as John Crane, Flowserve, Chesterton and AES
  • Much more...


  • Shaft drops easily by loosening coupling bolts, and engages by tightening the coupling bolts
  • Shaft only drops 1/2" eliminating steady bearing disengagement
  • No need to pull shaft up through gearbox or in-tank shaft supports
  • Much more...

Shafting is straightened to tight tolerances for long seal life and smooth operation – less than 0.003 inches total run out per foot of shaft length (0.25 mm per meter). Custom couplings, impellers, shafts and steady bearings are available upon request, including sanitary designs.

Types of Shafts

Shafting is supplied in a single piece design or in rigidly coupled sections for easy installation. For large diameter shafts, pipe shafting is a viable option with couplings and impeller hubs welded to the shafting. A wide range of materials and coating options are available.


To facilitate assembly in the field, extension shafts are attached to the drive shaft with flanged rigid couplings, eliminating the need for shafts to be installed through the gearbox. Optional in-tank couplings can either be removable tapered bore or welded simplifying installation of long shafts.

Steady Bearings

Steady bearings are available to help support extremely long shafts. Cup tripod, bracket and pad-type steady bearings are standard design options.

Extended Keyways

Extended keyways for adjusting impeller location offer process and design flexibility.

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