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Stenner M128 Peristaltic Pump
- 1:128 Medicator - M128 Series



Stenner M128 Peristaltic Pump - 1:128 Medicator - M128 Series

The M128 peristaltic pump delivers reliable injection at a 1:128 proportion for livestock water treatment.

The M128 series was specifically designed to inject solutions at a 1:128 ratio to treat livestock water with sanitizers, disinfectants, nutrients and medications. Also referred to as a medicator, the pump will automatically meter solution proportional to the water flow at a rate of one ounce of solution to 128 ounces of process water. For convenient and quick installations or turnkey operations, the M128 System is equipped with the pump and corresponding dry contact 3/4" or 1" Water Meter mounted on a heavy duty panel.

How It Works

The pump is actuated by water flow from a signal from a dry contact water meter. It has a cable with four lead wires; two are connected to the water meter. Installations with a house controller can utilize the two remaining wires to register water consumption to the controller. The standby setting can disable the pump while the internal relay allows the pulse water meter to register water consumption with the house controller. The pulse dial is adjustable to work with a dry contact water meter with pulse rates of 1, 2, 4 or 10 pulses per gallon or 1 pulse per liter. The pump is pre-set at the factory to operate with a specific tube size.

Unique Stenner Features

What sets the M128 apart from other medicators is the simple service which is periodic replacement of the pump tube and one piece check valve at the injection point. Read about Stenner’s QuickPro® pump head and effortless tube replacement.


The M128 series is available as two models, the M05 or M07. The primary differences are the output capability and pressure rating. Most livestock operations have a pressure reducer in place to drop pressures to a manageable level at the drinker lines. Injecting after the pressure reducer is an option, if higher outputs are needed.

  • M07: 3.5 oz/min up to 100 psi (105 ml/min up to 6.9 bar)

  • M05: 8.4 oz/min up to 25 psi (249.7 ml/min up to 1.7 bar)

Advantages of Stenner’s Peristaltic Pumps

  • Solution is not in contact with moving parts and runs through a food grade pump tube.

  • Pump head requires no valves, allows for easy maintenance.

  • Self-priming against maximum working pressure, foot valve not required.

  • Pump does not lose prime or vapor lock.

  • Pumps off-gassing solutions and can run dry.

  • Output volume is not affected by back pressure.

Product Manual
Chemical Resistance Guide


0-25 psi (0-1.7 bar)

Model Item No.
Tube #
M05 M05 #5
Approximate Output @ 50/60Hz
8.4 3.9 95.0 249.7 14.9 359.6

Maximum system water flow for 1:128 dosing is 8.4 gallons/minute or 31.8 liters/minute.

26-100 psi (1.8-6.9 bar)

Model Item No.
Tube #
M07 M07 #7
Approximate Output @ 50/60Hz
3.5 1.6 40.0 105 6.3 151.4

Maximum system water flow for 1:128 dosing is 3.5 gallons/minute or 13.2 liters/minute.

Alternative Sizing For M07 Model Using 1 pulse/gallon Meter

Dosage oz/gal Dosage Ratio Max. System
Water Flow
Pulse Setting
1.0 1:128 3.5 1
0.50 1:256 7.0 2
0.25 1:512 14.0 4

NOTE: 1 oz = 29.57 ml ; 1 gallon = 3.78 liters. Contact factory for assistance with sizing.

NOTE: Injection check valve included with pumps rated 26-100 psi (1.8-6.9 bar)

exclamation NOTICE: The information within this chart is solely intended for use as a guide. The output data is an approximation based on pumping water under a controlled testing environment. Many variables can affect the output of the pump. Stenner Pump Company recommends that all metering pumps undergo field calibration by means of analytical testing to confirm their outputs.


Maximum Operating Temperature 104°F (40°C)
Maximum Suction Lift 25 ft (7.6 m) vertical lift, based on water
Motor Type 24VDC, 2.0 A, Brushed DC, 1/30 HP
Duty Cycle Continuous
Motor Voltage (Amp Draw) 120V 60Hz 1PH (0.5)
220V 60Hz 1PH (0.33)
Power Cord Type SJTOW
Power Cord Plug End 120V 60Hz NEMA 5/15
220V 60Hz NEMA 6/15
Materials of Construction
All Housings Polycarbonate
Pump Tube & Check Valve Duckbill Santoprene®*, FDA approved
Pump Head Rollers HDPE
Roller Bushings Oil impregnated sintered bronze
Suction/Discharge Tubing,
Ferrules 1/4"
Polyethylene, FDA approved
Tube Fittings, Check Valve Fittings Gray fittings: Type 1 Rigid PVC, NSF listed
Black fittings: PP, NSF listed
Connecting Nuts PP or Type 1 Rigid PVC
Suction Line Strainer PP or Type 1 Rigid PVC body with Type 1
Rigid PVC cap, NSF listed; ceramic weight
All Fasteners Stainless steel
Pump Head Latches Polypropylene


Listings vary by model.

* Santoprene® is a registered trademark of Exxon Mobil Corporation.
** Versilon™ is a registered trademark of Saint-Gobain Performance Plastics.
† Pellathane® is a registered trademark of The Dow Company.

Pump Dimensions

Shipping Weight: 10 lbs (4.5 kg)

Box Dimensions: 14 x 9 x 9 in. (35 x 23 x 23 cm)



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Metex Corporation Limited has been providing superior products and services to the process control, chemical treatment, waste water, industrial and manufacturing industries for over 25 years. It is our goal to continually provide our customers with the best possible equipment, technology, and service.


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