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Installation and Operating Instructions for the FD95 Fertilizer Injector

FD95 Diagram

FertigationDirect injectors satisfy all USA federal and state regulations for fertigation and chemigation injectors when installed and operated properly. Please read these instructions carefully before installing and operating your new injector.

Warnings

General

It is the user’s responsibility to ensure that this equipment is installed and operated in accordance with all federal, state, local and private safety and environmental regulations, codes and standards. This equipment should be operated only by personnel who understand its function and purpose.

Chemical/fertilizer safety

    • Follow all chemical and fertilizer label instructions.
    • Make sure backflow preventers and other devices required for chemigation and fertigation in your area are properly installed and functional.
    • Wear proper protective gear when handling chemicals and fertilizers.
    • If injector leaks, discontinue use until repairs have been made.
    • Discontinue use of injector if any safety feature becomes inoperative.
    • Make sure that supply tanks are vented. Injectors create a vacuum which can collapse an unvented tank.

Electrical safety

WARNING: Dangerous voltage is present!
    • Electrical installation must be made by qualified personnel.
    • Follow all applicable electrical codes.
    • Make sure injector is properly grounded.
    • Make sure injector is supplied with the correct voltage.
    • Make sure branch circuit is properly sized and fused.
    • Interlock the injector with the pump or valve that supplies water to the irrigation system, so that the injector cannot run unless water is flowing in the irrigation line.
    • Protect electrical components from water.
    • In the event of any electrical problem, do not use injector until it is repaired.

Other precautions

    • Protect the injector from freezing. Before the injector is exposed to freezing temperatures, flush and dry fertilizer lines by first injecting water, then injecting air until no traces of water can be seen in the flowmeter. Then drain the injector's pump by disconnecting both water line connections and tipping the injector vertically, pump end down, so that all water drains from the pump housing and water lines. DO NOT USE ANTIFREEZE TO WINTERIZE THE INJECTOR, AS ANTIFREEZE IS CHEMICALLY INCOMPATIBLE WITH SOME PARTS OF THE INJECTOR.
    • Avoid pump seal damage: do not run the centrifugal pump without water; do not block or restrict the pump inlet or outlet.
    • It is the user’s responsibility to ensure that injected fertilizers are compatible with the injector’s materials. If fertilizers cause corrosion, softening or cracking of any part of the injector, discontinue use and rinse before further damage occurs and before the condition becomes hazardous to humans or the environment.

Should you have any questions, or if any of the above warnings are unclear, please contact FertigationDirect.com.

Mounting the Injector

Before mounting the injector, read and heed the WARNINGS section of this document.

  1. Review the website photo of the FD95 installed on a pipeline and the labelled drawing at the top of this page.
  2. Familiarize yourself with the FD95 sub-assemblies: Remove the FD95 sub-assemblies from the shipping box and assemble them near your horizontal irrigation pipeline with the motor end upstream. Confirm that the planned installation location is suitable and remove any obstacles to installation. Separate the sub-assemblies.
  3. Prepare the pipeline: De-pressurize the pipeline. Install one 1 1/2" male pipe thread (MPT) connection and one 1" male pipe thread (MPT) in the top surface of the irrigation pipe. These should be one foot apart, at least three feet downstream from your chemigation valve or backflow preventer. Welded-in half nipples are typical for metal pipelines; saddle fittings or tees with male inserts are typical for plastic pipelines. To avoid underperformance and/or damage the injector’s pump, don't do anything that could restrict flow through these half nipples.
  4. Install the valve sub assemblies: Apply Teflon tape to the half nipples. Attach the 1 1/2" valve sub assembly and the 1" valve sub assembly onto the pipeline connections.
  5. Place the injector's pump assembly onto the irrigation pipe just upstream of the half nipples. Slide the motor/pump assembly into place and mate and close both arms of the camlock fitting. Stabilize the motor/pump so it remains in place while subsequent operations are performed.
  6. Install motor baseplate clips: Install 1 clip into each of the 4 slots on the motor foot plate so that the rectangular hole in each clip is beneath the foot plate.
  7. Install mounting strap: Pass one 4 foot long stainless mounting strap around the pipe and through rectangular holes in two clips. The strap passes between the motor foot and the pipe. Engage the worm gear end with the other end of the strap and tighten. Make sure the clips remain in place on the motor foot while tightening is underway. Hint: a power screwdriver/drill with a socket attachment works far better than a nut driver or screwdriver for this task.
  8. Repeat the preceeding step for the other strap.
  9. Install the flowmeter/venturi assembly: Align the venturi/flowmeter assembly onto the pump discharge and tighten the camlock fitting.
  10. Tighten the hose clamp and connect the hose camlock fitting to the downstream pipeline fitting.
  11. Mate the outlet assembly's camlock fitting to the pump assembly's camlock fitting. Close both arms of the camlock fitting.
  12. Connect fertilizer hose: Connect and clamp your fertilizer tank hose to the injector's 3/4" hose barb.

Fertilizer Tank

Make sure that the size, materials and mixing capabilities of your fertilizer tank are suitable for the fertilizer you are injecting. The tank should be within a few feet of the injector, vented, and high enough so that its liquid level is within about two feet of the highest part of the injector when the tank is almost empty. All hose and fittings between the fertilizer tank and the injector should be at least 3/4" in diameter. The tank should have a shut-off valve at the outlet.

Electrical Installation

WARNING: Dangerous voltage is present!

NOTE: Electrical interlocks must be provided to make sure that the injector cannot operate unless irrigation water is flowing.

FertigationDirect.com recommends that each injector (if more than one are installed) be powered from a separate, properly sized and protected branch circuit. For the three-phase FD95, be sure to check for proper rotational direction of the injector's motor (clockwise when viewed from the motor end of the pump).

    • Electrical installation must be done by qualified personnel:
    • Follow all applicable electrical codes.
    • Make sure branch circuit is properly sized, fused and controlled.
    • Make sure injector is properly grounded.
    • Make sure injector is supplied with the correct voltage.
    • Protect electrical components from water.
    • In the event of any electrical problem, do not use the injector until it is repaired.

How the Injector Works

Operation

A portion of the water to be treated is drawn from the pipeline into the injector's centrifugal pump and forced through an efficient venturi before returning to the pipeline. Vacuum from the venturi draws fertilizer through a flowmeter and a manual flow control valve into the water stream. Other valves in the fertilizer line prevent fertilizer backflow and unintended forward fertilizer flow. The fertilizer enters the injector downstream of the centrifugal pump, greatly reducing the possibility of pump corrosion.

Safety features

Vacuum injection reduces the possibility of chemical/fertilizer escape. A check valve at the venturi prevents backflow of water into the fertilizer tank and an automatic shutoff valve prevents injection line flow if the pump loses pressure. Discontinue use of the injector until repairs are made if either of these devices fails.

Flow capacity

A properly-installed FD95 injector injects most fertilizer solutions at any set rate between 10 and 95 gallons per hour, as long as the pipeline pressure is at or below 70 psi and the injector is not installed at a high altitude. If fertilizer density or viscosity is significantly greater than that of water, or if the injector is installed at higher altitudes, maximum injection rate may decrease slightly.

Operating the Injector

  1. Only qualified personnel, who understand the injector’s function and purpose, and who have thoroughly read and understand this document, should be allowed to operate the injector. Read and heed the WARNINGS section of this document.
  2. Inspect the FD95 and its pipeline connections each time before the injector is operated. Make sure fittings and hose clamps are tight. If anything is damaged, replace it before operating the injector.
  3. During initial start-up FertigationDirect.com recommends that operators inject water. This allows operators to become familiar with the injector and to make sure the installation is correct and leak-free before using it to inject fertilizer.
  4. Prepare fertilizer as required. Make sure enough is available for the planned injection run. Connect the fertilizer tank to the injector and open any fertilizer line valve(s). Check for leakage and repair any leaks before starting the FD95.
  5. Start the irrigation system. Prime the injector's pump if necessary by carefully opening one arm of the camlock fitting at the pump outlet. This will allow air trapped in the pump to bleed out prior to starting it. Re-close the camlock arm after water begins to seep from the camlock fitting. Ensure that both camlock arms are fully closed before starting the injector.
  6. Connect the injector to a proper source of electric power and switch it on.
  7. Use the flowmeter and metering valve to set the injection rate. The flowmeter setting should be used only as a guide. Actual injection rate will vary slightly according to the density and viscosity of the liquid being injected. The FD95 injector’s accuracy as viewed directly on its flowmeter is more than adequate for most fertigation tasks. However, if more precise injection is desired, calibrate the injector using a known volume of your fertilizer and a stopwatch.
  8. After the desired period of injection, switch off electric power to the injector.
  9. If the injector will stand for more than a few days before being used again, rinse the injection line after use by injecting water for a short time to prevent build-up of dried fertilizer in the line.

The injector will not be harmed if the fertilizer tank runs empty during operation. However, after the tank is emptied, the injector continues to pull air through the injection line. If residues tend to dry to a scale or turn gummy, you should avoid prolonged operation with an empty tank.

Troubleshooting the Injector

Centrifugal pump problems

Centrifugal pump problems can usually be detected by sound -- different sounds come from a spinning pump under two conditions:

    • Normal flow: smooth, low, purring sound
    • No flow/partial flow (cavitation): high pitched whining or rough, grinding sound (NOTE: a properly operating venturi also makes a somewhat "gravelly" sound. Be sure to determine where the sound is coming from.)

If there is no flow or if there is cavitation at the centrifugal pump:

    • Is pump connected to the pipeline properly?
    • Was the pump primed properly?
    • Is there air in your irrigation line?

Injection rate problems

If injection rate is too low, check the following factors:

    • Is the centrifugal pump working properly?
    • Is the injector installed too high relative to liquid level in the fertilizer tank?
    • Is there a vacuum leak in the fertilizer tank line? Very small leaks can cause serious reductions in injection rate.
    • Are there any other vacuum leaks? (NOTE: Vacuum leaks upstream of the flowmeter result in bubbles in the flow tube.)
    • Are all hose connections tight?
    • Is the metering valve set correctly?
    • Is the EPA valve opening when the injector is started?

Electrical problems

If the problem is still not identified check the following factors:

    • Is the pump rotating in the right direction (clockwise when viewed from the motor end)?
    • Is the voltage right?
    • Is the circuit sized properly?
    • Are the breaker and overload relay sized and set properly?

Testing the Injector's Environmental Safety Features

Owners of fertigation injectors are responsible for maintaining their environmental safety features. Government regulations require periodic testing of fertigation and chemigation equipment.

The following test procedures will assist users and regulators in confirming that the environmental safety features of the injector are working properly. These procedures must be performed in such a way that they comply with all environmental and personal safety regulations concerning chemical handling. These procedures must be performed while the system contains water instead of fertilizer solutions, to avoid possible spillage of fertilizer.

Test 1: Irrigation line/injector interlock

Requirement. The injector must not deliver fertilizer to the irrigation pipeline unless irrigation water is running.

Background. Injectors must be installed by the user so that they cannot run unless water is running in the irrigation line. For electric powered injectors, the user installs an electrical interlock in the injector’s electrical supply so that the injector pump cannot start or run unless the irrigation line pump is running.

Purpose of test. This test determines whether the electrical interlock described above is working properly.

Precautions. Perform this test only after flushing all fertilizer out of the injection line. Only water should be in the injection line and fertilizer tank when performing this test.

Test conditions. Begin this test when the main irrigation pump is not running and the injector’s pump is not running.

Procedure:

  1. Attempt to start the injector (it should not start).
  2. Switch the main irrigation pump on, so that water runs through the irrigation line.
  3. Attempt to start the injector (it should start).
  4. While the injector is running, shut off the main irrigation pump (the injector should shut off automatically).

Evaluating results. The test is passed if the injector starts and stops as described.
The test is failed if the injector starts when it should not or if it does not stop when it should.

What next? If an electric powered injector starts and/or runs when the main irrigation pump is not running, the problem is most likely with the interlock device. Use proper troubleshooting procedures at the electrical interlock between the irrigation pump and the injector’s power source. Make repairs or corrections as necessary.

Test 2: Injection line check valve

Requirement. Water from the irrigation line must not run back into the fertilizer tank because this could overflow the tank and risk spilling fertilizer.

Background. A check valve is provided in the injector’s injection line to prevent water from flowing back through this line to the fertilizer tank.

Purpose of test. This test determines whether the injection line check valve is working properly.

Precautions. Perform this test only after flushing all fertilizer out of the injection line. Only water should be in the injection line and fertilizer tank when performing this test.

Test conditions. Perform this test when the main irrigation pump is running and the injector’s pump is not running.

Preparation. Locate the injection line check valve at the side inlet of the venturi. Locate the union connection on the metering valve at the top of the flowmeter.

Procedure:

  1. Open the injector’s metering valve.
  2. Unscrew the knurled union nut on the metering valve, pull the valve ends apart gently and pivot the flowmeter on its pipework so the metering valve's interior is visible.
  3. Check for water leaking from the check valve through the metering valve.
  4. Pivot the metering valve back into position and re-tighten its union nut finger tight.

Evaluating results. The test is passed if there is no leakage from the check valve. The test is failed if there is leakage from the check valve.

What next? If the test finds leakage, correct the failure by cleaning or replacing the check valve assembly as appropriate.

Test 3: Injection line EPA valve

Requirement. When irrigation water is not flowing, the static head pressure in the fertilizer tank may be greater than the pressure in the irrigation pipeline. Under this condition, liquid must not drain from the fertilizer tank into the irrigation pipeline.

Background. A hydraulically actuated, normally closed valve (the "EPA valve") is provided in the injector’s injection line to prevent fertilizer from flowing into the irrigation pipeline unless water is being pumped through the irrigation pipeline.

Purpose of test. This test determines whether the EPA valve is working properly.

Precautions. Perform this test only after flushing all fertilizer out of the injection line. Only water should be in the injection line and fertilizer tank when performing this test.

Test conditions. Perform this test when the main irrigation pump is not running and the injector’s pump is not running.

Preparation. Locate the injection line check valve at the side inlet of the venturi. Locate the hose that brings fertilizer from the tank to the injector’s inlet barb.

Procedure:

  1. Close the fertilizer tank outlet valve.
  2. Disconnect the fertilizer tank hose from the injector’s inlet barb by loosening the hose clamp and twisting the hose off the barb.
  3. Unscrew the knurled union nut on the metering valve, pull the valve ends apart gently and pivot the flowmeter on its pipework away from the valve, so the interior of the top flowmeter connection is visible.
  4. Connect a source of pressure (at least 10 psi but not more than 75 psi) to the injector's fertilizer inlet barb.
  5. Check for leakage from the top of the flowmeter.
  6. Pivot the flowmeter back into position and re-tighten the valve's union nut finger tight.

Evaluating results. The test is passed if the EPA valve does not leak through. The test is failed if the EPA valve leaks through.

What next? If the test finds leakage, correct the failure by replacing the EPA valve.

Rate Calculation Examples

Example 1: Fertilizer application through a center pivot

Variables:

    • Total acres under the center pivot
    • Revolution time for a complete circle
    • Actual nitrogen (N) required per acre
    • Actual N per gallon of fertilizer solution

Situation:

    • 140 acres under pivot
    • Circle revolution time is 16 hours
    • 30 pounds actual N required per acre
    • 3 pounds actual N per gallon of 28% solution

Calculations:

  1. 140 acres x 30 pounds N = 4,200 pounds N required for one revolution
  2. 4,200 pounds N divided by 3 pounds N per gallon = 1,400 gallons of 28% N solution
  3. 1,400 gallons of solution divided by 16 hours = 88 gallons per hour injection rate
  4. Set injection rate at 88 gallons per hour

Example 2: "Spoon-feeding" fertilizer through a drip system

Variables:

    • Total acres in zone to be fertigated
    • Hours of irrigation for that zone
    • Required application rate per acre
    • Size of fertilizer tank

Situation:

    • 40 acres in zone to be fertigated
    • Zone is to be irrigated for 2 hours
    • 2 gallons of fertilizer concentrate required per acre
    • Fertilizer tank holds at least 20 gallons

Calculations:

  1. 40 acres requires 80 gallons fertilizer concentrate in tank
  2. Fill tank to at least 80 gallons
  3. Divide 80 gallons by 2 hours = 40 gallons per hour injection rate
  4. Set injection rate at 40 gallons per hour

Calibration:

The reading on the injector's visual flowmeter is influenced by the viscosity and density of the material being injected. Because different fertilizers have different viscosities and densities, additional calibration of the injection rate may be required, depending on the level of accuracy required. This is done as in the following example:

    • (40 gallons per hour) / (60 min. per hour) = 0.67 gallons per minute
    • Place a known volume of fertilizer in a small calibrated container. Place the supply end of the injection hose in the container. Use a stopwatch to time the injection of the amount. Adjust injection rate until you can time 1 minute per 0.67 gallons injected. Record the flowmeter setting at this injection rate.
    • Be sure to take all precautions required for the materials you are handling.

Alternatively, you can make careful observations of the usage rate from your fertilizer tank if it has a volume scale.