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Model 20 HT/GT Agitators

Our Model 20 HT/GT agitators are designed for a wide range of services in the chemical, pharmaceutical, ethanol and biofuels, water and wastewater, flue gas desulfurization, power, and other general process industries. 

render of model 20 HT GT Agitator
  • Description Description
  • Resources Resources

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.

Our 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 Model 20 HT/GT agitators are designed to meet AGMA, OSHA, ANSI, IEC, DIN, EU, and ATEX standards and requirements.

Chemineer Model 20 HT/GT agitators also offer:

  • ChemSeal
  • 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

NSF/ANSI 61 and NSF/ANSI 372 certified
This product is Listed by UL. Representative samples of this product have been evaluated by UL and meet applicable safety standards.

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 and 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 nonsynthetic lubrication over competitive single-reduction designs
  • Highest efficient gearing available reduces energy costs
  • Reduces wear rate for 20+ years of service life

Housing and Lubrication


  • Cast gearbox
  • Dry well seal
  • Grease and bath lubrication
  • Standard rust and oxidation oils


  • Modular designs between right angle (HT) and parallel shaft (GT)
  • Eliminates lubrication leaks that are common in commercial gearboxes with no dry well
  • Ensures vital lubrication to gears and bearings at all operating speeds, eliminating internal and external lubrication pumps
  • No synthetic lubrication 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


  • Shaft drops easily by loosening coupling bolts and engages by tightening the coupling bolts
  • Shaft only drops ½ in., eliminating steady bearing disengagement
  • No need to pull shaft up through gearbox or in-tank shaft supports

Shafting is straightened to tight tolerances for long seal life and smooth operation less than 0.003 in. 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 
for adjusting impeller location offer process and design flexibility.

  • Chemineer Model 20 HT/GT Agitators Brochure (English)
  • Chemineer Model 20 HT/GT Agitators Brochure (German)
  • Chemineer Model 20 HT/GT Agitators Brochure (Russian)
  • Manual 701: Model 20 GT (Case Sizes 21, 22) Double Reduction
  • Manual 702: Model 20 GT (Case Sizes 21, 22) Triple Reduction
  • Manual 703: Model 20 HT (Case Sizes 21, 22)
  • Manual 704: Model 20 GT (Case Size 23) Double Reduction
  • Manual 705: Model 20 GT (Case Size 23) Triple Reduction
  • Manual 706: Model 20 HT (Case Size 23)
  • IO&M Manual 711.03: 20 GTN/GTNC/GTNS, 20 HTN/HTNC/HTNS
  • IO&M Manual 712.01: 20 GTA/GTL/GTNT, 20 HTA/HTL/HTNT
  • IO&M Manual 713.02: 20 GTD/GTP, 20 HTD/HTP
  • IO&M Manual 731.02: 20 GTN and HTN SpacerSpool
  • Supplemental IO&M Manual 740: 21 GTA/GTL/GTNT Angle Mount
  • IO&M Manual 415.01: GTD/GTP Style Agitators
  • Manual 415.1: GTD/GTP Supplement1 - Mounting
  • Manual 415.2: GTD/GTP Supplement2 - Angle Mounting
  • IO&M Manual 416.01: GTA/GTL/GTNT Style Agitators
  • Manual 416.2: GTA/GTL/GTNT Supplement2 - Angle Mounting
  • IO&M Manual 417.01: GTN/GTNC/GTNS Style Agitators
  • Manual 420.01: GT Gear Drive Case Sizes 1, 2, 3, 4 Double Reduction
  • Manual 421.01: GT Gear Drive Case Sizes 3, 4 Triple Reduction
  • Supplement CT/GT Conversion