S Series Metering Pumps Performance Benefits

Electronic solenoid pumps that provide reliable, economical, and eco-friendly chemical injection

Hydra-Cell S Series metering pumps are ideal for low-flow, low- pressure requirements in a wide range of chemical processing applications. They will complement other Hydra-Cell Seal-less Pumps and Hydra-Cell Metering Solutions pumps in many different types of installations.


They are ideal for low-flow, low-pressure requirements and will complement other Hydra-Cell Seal-less Pumps and Hydra-Cell Metering Solutions pumps in many different types of installations.

SM manual control units as well as SP/ST/SA pulse/analog control models offer up to 300 strokes per minute. Maximum flow rates range from up to 25 ml/min (0.40 gph / 1.5 lph) to 220 ml/min (3.49 gph /13.2 lph) depending on model.

Several materials of construction choices and various design options result in pumps ideal for specific applications including chemical injection, high-pressure boiler, high-viscosity fluids, outgassing fluids and more.


Versatile, Economical and Easy to Operate

  • Manual-control SM models feature a simple hand-operated dial with stroke adjustment from 15 to 300 strokes per minute.
  • SP, ST & SA models have pulse-in (SP), pulse-in with timer (ST) or pulse-in/analog-in (SA) control and stroke adjustment in 1-stroke increments up to 300 strokes per minute.
  • SP, ST & SA models also feature simple key operations and intuitive user interface - a bright, sharp LED display is clearly visible in lowlight as well as high-glare areas.
  • “Eco-friendly” environmentally sound operation is standard with SP, ST & SA models - this feature can lower power consumption up to 55%.
  • Double-ball check valve ensures accurate metering and reduces the chance of water hammer.
  • PVC, PVDF, 316SS, and Acrylic liquid end component choices to match specific applications.
  • Model available with a pump head that can be moved in three directions to provide flexibility of installation.
  • Dust-proof and wash down capable (IP65) - ideal for indoor or outdoor use.
  • Pump housing is molded from high-impact PPO, an engineered thermoplastic that provides dimensional stability and excellent resistance to heat.
  • Power supply range for operation between AC100 and 240V (±10%) with plugs available for North America, Europe, UK, and Asia.
  • Fast, easy maintenance as liquid-end parts can be disassembled and replaced by simply detaching four bolts.

Safety Mechanisms to Handle Air Build-up

S Series pumps feature an innovate design to minimize dead space and prevent air entry and build-up inside the pump. In case air or another gas does enter the pump and impede chemicals from being discharged, each S Series model has an easy-to-use mechanism to remove the air or gas.

Manual Air Release Valve

  • With the pump turned off, attach one end of the appropriate tubing supplied with the pump to air release port and the other to the supply tank or other container.
  • Switch the pump on to the maximum flow rate and then turn the air release knob counterclockwise 1 to 1-1/2 rotations.
  • The air/liquid will exit the pump via the port and tubing. After the air is fully purged, turn the air release valve back clockwise until tight, and then switch off the pump.


S Series models 030, 060, and 100 feature a manual air release valve.

Manual Air Release Valve with Integral Relief Valve Option

  • The integral air release valve operates similar to the manual relief valve with one important difference: the knob is always turned clockwise.
  • After switching off the pump, attaching the hose, releasing the discharge side pressure, and setting the flow rate on maximum, turn the air release knob clockwise approximately 90 degrees.
  • There will be a gap between the knob and the retaining nut. Once the air is purged, turn the knob clockwise again until a “click” is heard. Then switch off the pump.

S Series pump models 03R, 06R, and 10R are equipped with an integral air release valve and external knob.

Air Release for Stainless Steel Models

  • Switch the pump off and then slightly loosen the air release nozzle, turning it counterclockwise. Make sure the nozzle does not disconnect from the pump.
  • Connect the hose pump to the nozzle on one end and the tank or container on the other and then switch the pump on.
  • After the air or chemical is expelled, switch off the pump, remove the hose, and then turn the nozzle clockwise until it is tight.


S Series Stainless Steel models (ST type pump heads) feature an air release nozzle.

Safety Mechanisms to Prevent Air Lock (Outgassing)

  • Outgassing results when the fluid pressure drops below the saturation pressure of a gas dissolved in a liquid. If this occurs, gas comes out of the solution and builds up inside the pump. When air enters the pump head, it prevents the chemicals from being discharged.
  • S Series pumps for outgassing fluids (e.g. Sodium Hypochlorite) with Acrylic pump heads feature an innovative design to minimize dead space and prevent air entry and build-up in the pump.
  • If air enters the pump, or if outgassing occurs, the Acrylic pump head models feature safety mechanisms to combat air lock and outgassing. The transparent liquid ends enable the operator to see whether air is present in the pump head.

Air Release Port
Chemical Discharge Port

SM (manual) models with Acrylic pump heads discharge entrapped gas from the air release port. Gas or bubbles from the chemical tank are suctioned through the air release joint and expelled.

Automatic Degassing Joint

Select SP/ST/SA models with Acrylic pump heads feature a degassing joint that eliminates virtually all causes of air entrapment. Air is purged without infiltration of the pump head and goes out through discharge piping.



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