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Home Pumps S128 Series

S128 Series

1:128 dosing for process flows up to 10 gpm


  • Evenly injects especially at low flows
  • Activate multiple pumps with one meter
  • Leak detection and optional relay
  • LED indicators
  • Totally enclosed housing
  • Simple tube replacement
  • 2 year warranty

1:128 Pump Adjusts to System Flow Rate for Even Distribution of Product

Activated by a dry contact pulse water meter, the S128 automatically injects solution into the water line proportional to the system water flow at a ratio of 1 ounce of solution to 128 ounces of process water. As the pump registers dry contacts, it delivers the precise ratio.

The pump has three speeds to automatically adjust the injection rate when the water system flow rate increases or decreases. This flow response design allows the pump to evenly and proportionally inject solutions especially at low flow rates.

The S128 and the low flow VPD water meter are ideal for early stage poultry flocks and swine nurseries when water flow is minimal. The S128 can inject undiluted chemicals directly into the water line eliminating water restriction and the daily mixing of stock solutions. In addition, the pump is unaffected by poor water quality.


  • Potentiometer: Prime, 1 PPG, 1 PPL, 10 PPG, Reset Tube Timer, Standby
  • Output Relays: Signal Repeater Leak Detect, Drive Fault, Low Level
  • LED Indicators: Leak/Fault, Overrun, Change/Level, Power/Standby
  • Clear cover on control panel for moisture protection
  • Enclosed housing with NEMA 4X rating

Built-in Signal Repeater Relay

The built-in signal repeater relay repeats the pulse signal from the water meter to another pump or house controller. If using a meter to register water consumption to the house controller, an additional meter is not required to activate the pump.

Tube Change Timer

Set the Tube Change Timer DIP switches with the number of hours you want the pump to run before the CHANGE LED is activated. When the set time is reached the change/level LED is lit solid red. The standby setting allows the tube replacement without disconnecting the pump.

Leak Detect Setting and Output Relay

Set the pump’s DIP switch  to stop or to continue to run when a leak is detected. Set the optional output relay to notify another device if a leak occurs.

Signal Inputs

The pump has three dedicated inputs to receive a signal from another device.
PULSE Receives a pulse from a dry contact water meter to activate the pump.
STANDBY Remotely start or stop the pump when a dry contact input is sent to the pump. Replace tube without disconnecting pump
LEVEL  Input from a fluid level device indicates a low level in the solution tank. The Level Input may be used with the low level output relay.

Stenner Peristaltic Pumps Advantages

  • Self-priming against max. working pressure; foot valve not required
  • Solutions do not contact moving parts
  • Pump head requires no valves, allows for easy maintenance
  • Does not lose prime or vapor lock
  • Pumps off-gassing solutions and can run dry.
  • Output volume is not affected by back pressure.
  • Tube replacement without tools

Flow Rate Outputs

 60 psi (4.1 bar) max.
Pump Tube Ounces
per Minute
per Minute
Approximate Output @ 50/60Hz
S4M8X 8X 10.0 295.7
NOTICE: The information within the charts above 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.

Technical Data

Flow Rate Output Control Fixed rate, interfaces with water meter
Reproducibility +/- 2%
Maximum Working Pressure 60 psi (4.1 bar)
Maximum Suction Lift 25 ft (7.6 m) vertical lift, based on water
Motor Type Brushless DC motor
Shaft rom (average maximum) 45
Duty Cycle Continuous
Maximum Viscosity 1500 Centipoise
Motor Voltage (Amp Draw) 120V 60Hz 1PH (0.6)
Power Cord Type 120V 60Hz  SJTOWA
Power Cord Plug End 120V 60Hz  5-15P
Cord Length 6 ft (1.8 m)
Classification Indoor/Outdoor
Maximum Operating Temperature 104°F (40°C)


Materials of Construction
All Housings Polycarbonate
Pump Tube Santoprene®* (FDA approved)
Ball Check Valve Components Ceramic ball (FDA approved); Tantalum spring; FKM seat & O-ring or
Ceramic ball (FDA approved); Stainless steel spring; EPDM seat; Santoprene®* O ring
Pump Head Rollers Polyethylene
Roller Bushings Oil impregnated  bronze
Suction/Discharge Tubing Polyethylene (FDA approved)
Tube and Injection Fittings PVC or Polypropylene (both NSF listed)
Connecting Nuts PVC or Polypropylene (both NSF listed)
Suction Line Strainer and Cap PVC or Polypropylene (both NSF listed); ceramic weight
All Fasteners Stainless steel
Pump Head Thumbscrew Stainless steel; PVC
Pump Head Support and Transition Sleeve Santoprene®*
Tube Pull PVC
Leak Detect Components Hastelloy®††; Stainless steel    

* Santoprene® is a registered trademark of Celanese International Corporation.
†† Hastelloy® is a registered trademark of Haynes International, Inc

Agency Listings


Pump Dimensions

Box Dimensions

14 x 9 x 10 in. (35 x 23 x 24 cm)

Shipping Weight

10 lbs (4.5 kg)


Dimensions & weight

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