DOTF Hydration Unit

Improving safety and efficiency

Dry-on-the-Fly (DOTF) hydration unit is designed to mix and hydrate different types of dry polymers for continuous-mix hydraulic fracturing operations. The unit provides the necessary mixing shear and hydration-tank volume to ensure complete hydration of the polymer before delivery to the blender.  

The DOTF unit disperses the polymer more efficiently and eliminates hydrocarbon-based liquid frac concentrate and mineral oils commonly used in fracturing treatments, reducing environmental impact. 

The unit features two dry-gel metering tanks, each capable of holding 3,000 lbm (1,360.8 kg) while its feeder can meter as much as 120 lbm (54.4 kg) of polymer per minute for fast, accurate mixing. It can hydrate guar and other standard dry polymers in either batch or continuous processing, eliminating the need for third-party blending, enhancing additive measurements and improving slurry quality. The control panel displays polymer rate, temperature, viscosity and water rate for real-time monitoring and control.  

Technical Data

Maximum envelope dimensions (trailer only)


43.8 in (13.2 m)


8 ft (2.4 m)


13.25 ft (4.0 m)

Gross Weight

60,000 lbm (22,220 kg)  /  (Includes 6,000 lbm [2,721.6 kg] of dry gel)

Ambient operating temperature


120°F (48.9°C) 


-40°F (-40°C)  /  (Equipment will operate at this temperature, but special procedures may be required to ensure gel hydration)

Hydration tank capacity

Nominal (Minimum)

160 bbl (25.4 m3)

Actual (Minimum)

180 bbl (28.6 m3)

Rate capability

Conventional Operation

100 bbl/min with 30 lbm/1,000 gal gel  /  (15.9 m3/min with 22 kg/3.8 L gel)

Dry-Gel Feeder (Two 4-in. Metalfab Feeders)

1–120 lbm/min (0.5–54 kg/min)