Choosing the Right Stenner Pump

How are you controlling the chemical pumping flow?

You can manually turn the pump on an off, connect the pump to a well pressure switch, use an analytical instrument with a 4-20ma output to tell the pump when to pump (and how much), use a dry contact water meter to proportionally inject the pumped chemical or use a fixed output pump with a programmable timer.

Using a Time Programmable Pump - The Stenner BDF series pump is a programmable pump that can dose .06 to 21.0 ounces per hour. This pump is programmable up to 24 dosage events per day and is available in a 24-hour and 7 day model. You simply have to choose the output pressure (25psi or 100psi) and the timer model. This series of pump would be ideal for grease traps, residential well dosing or any fixed volume process application where consistant dosing volumes and times are required.

Controlling Pump Flow with a 4-20ma signal - The Stenner SVP series pumps can be controlled via the 4-20ma output that is common for analytical instruments like pH or ORP meters. Only the SVP4 model of pump can accept a 4-20ma signal. This pump can be overidden manually in increments of 1% flow. This is the most accurate way to control dosage as it is the only method to assure exact dosage and under/over dosage by reading the exact concentrations in solution. This method would be ideal for pH adjustment, oxidation, or any process chemical application.

Controlling Pump Flow with a dry contact water meter - Applications where you want to control the dosing of chemical in proportion to the flow of water can be done using any Stenner pump along with a dry contact water meter and the Stenner PCM module. This method is ideal for residential/commercial water disinfection, coagulation, corrosion and scale control.

Turning the pump on and off manually or controlling flow with a well pump pressure switch- All Stenner pumps can be turned on and off manually to control pumping or turned on and off by wiring the power to a pressure pump well switch. Which series is right for you depends on whether you need to be able to change the output or not.

• The Stenner MP series pumps and Stenner MPHP series pumps are fixed output only
• The output for the M series Stenner pumps and MHP series Stenner pumps is adjustable in 5% increments up to the max listed for the pump
• The output for the SVP1 and SVP4 series of pumps is adjustable in 1% increments up to the max listed for the pump (due to variable speed motor)

How much pressure (in PSI) are you pumping against?

Stenner pumps are classified in two ranges of pressure - low pressure (up to 25psi) and high pressure (up to 100psi). In general, if you do not know the pressure you are pumping against but are sure it is 100psi or lower, you should choose a high presure pump. Pumping against pressure greater than 25psi with a low pressure pump can affect the output of the pump and can also damage the pump and is not recommended. The Stenner 45M series pumps and 45MP series of pumps are low pressure pumps. The Stenner MHP and MPHP series of pumps are high pressure pumps. Standard residential water pressure is normally above 25psi but below 100 psi so a high pressure pump should be chosen. Pressures above 100psi can damage residential plumbing systems.

What output range in GPD does your appliation require? Sizing your pump

The formula for calculating the required pump output is:

System Flow Rate(GPM) x Required Dosage(PPM) x 1440 (minutes in one day) / Solution Strength (PPM) = Pump Output in GPD

For example, sizing for a continuous flow application with a system flow rate of 10GPM with a required dosage of 4PPM using a 1 to 3 diluted solution of 6% sodium hypochlorite (1 part standard bleach, 3 parts water) would be:

10GPM x 4PPM x 1440 / 15,000PPM (6% bleach is 60,000PPM so diluted solution is 15,000PPM) = 3.84GPD

It is normally recommended to choose a pump capacity of double the needed output so in this case a pump with a maximum output of at least 8GPD.

An example of sizing a pump for a contacting head water meter feeding application (for non-continuous system flow applications where the pump is turned on by a contacting water meter) where the non-continuous system flow rate is 10GPM (typical household flow), the desired dosage is 4PPM (typical chlorine disinfection dosage), a water meter GPC rating of 1 GPC (1 Gallon Per Contact) and using the same diluted solution of bleach as above (diluted to 1.5% sodium hypochlorite or 15,000PPM):

Determine Chemical Injection GPM = 10GPM x 4PPM / 15,000 = .0027

Determine Contacts per Minute from Meter in Strokes per Minute = 10GPM (system flow rate) / 1 (Gallons per Contact Rating) = 10

Determine Pump Rated Output in GPD = .0027 (chemical injection GPM from above) / 10 (contacts per minute from above) x 125 (max strokes per minute of metering pump) x 1440 (minutes in a day) = 48GPD Pump Output Required

What type and size chemical tank do I need for my system?

You will need a chemical storage tank to store the chemical you are pumping into your application. Stenner offers two different sizes of polyethylene chemical tanks, 15 and 30 gallon, in two different colors - a natural opaque color and a grey color. The grey color tank is UV resistant for outdoor installions. The most popular series of Stenner chemical feed pump, the MHP high pressure adjustable pumps, are offered with a tank as a complete pre-mounted system called the Stenner STS Feeder and Tank systems. You can also buy the tank for any pump complete with mounting hardware separately.

Should I choose 1/4" or 3/8" tubing with my pump? Should I choose white or black tubing?

1/4" tubing works for most people and most applications. Selecting 3/8" diameter tubing does not affect pump output but it may help with pump priming when pumping viscous liquids. Black tubins is UV resistant for outdoor applications. Both white and black tubing are made from the same material.

Which pump tube material is chemically compatible with my pumped solution?

The wetted parts of a Stenner pump are the pump tube, suction/discharge tubing, suction valve and injection valve. You should also verify the chemical compatibility of your chemical storage tank which for Stenner pumps is normally polyethylene. Below is a list of chemicals and their relative compatibility with the materials of construction of a standard Stenner pump and tank combo (PVC, LDPE, and Santoprene). Siemens makes no warranty, expressed or implied, as to the accuracy of this guide or any materials' suitability for fitness or purpose for any application. User assumes all risk and liability for use of this guide.

Ratings Key

• A = Fluid has minor or no effects
• B = Fluid has minor to moderate effects
• C = Fluid has severe effects
• * - No data available