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Frequently Asked Questions - Chemical Feed
  • My chemical feed pump gets air bound at night, what’s wrong with my pump?
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    • More than likely, there isn‘t anything wrong with your pump. If you’re pumping a gaseous chemical such as sodium hypochlorite (bleach) or hydrogen peroxide, then you probably have gas forming inside the suction tubing or pump head. This gas is what’s locking up your pump and keeping it from pumping. In most situations, you can manually re-prime the pump and everything is fine for the time being. For a more permanent solution, you need a way to get that gas out automatically when you’re not around.
      Most of the solenoid driven diaphragm chemical feed pump manufacturers have addressed this problem and have developed ways to eliminate this problem. LMI and Pulsafeeder have developed a degassing head which bypasses the gas through a third valve port on the pump head and eliminates the need for a 5 function bleed valve. They currently have conversion kits for a limited number of Pulsafeeder models so depending on your pump model, this may or may not be an option.
      Depending on your application, Stenner offers a peristaltic pump that is ideal for feeding gaseous chemicals. The peristaltic design pushes the bubbles through the pump head and will not lose prime when pumping gaseous chemicals.
  • What can I do to lessen the “hammering” on the discharge piping from my mechanically driven diaphragm type chemical feed pump? It looks like its going to break.
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    • Most of the manufacturers of mechanically driven, diaphragm type chemical feed pumps recommend that you install a pulsation dampener on the discharge line to reduce the excessive vibration and hammering that is caused by the pulsating action of these pumps. The natural pulsating action of these pumps is enough to rupture pipe, fittings or valves and could lead to a potential disaster!
      A pulsation dampener is a pressurized vessel with a elastomeric bladder that acts like a shock absorber and delivers a constant, smooth flow. If you are frequently replacing cracked fittings on the discharge side of your pump, you may want to consider installing a pulsation dampener. Please make sure to check for chemical compatibility when choosing a pulsation dampener.
  • We’re looking to get rid of our chlorine gas disinfection system at our wastewater plant. What other options are available for disinfecting our effluent?
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    • USABlueBook offers several options. If you want to stick with chlorine, you can use a tablet feeder with chlorine tablets. A flow-through tablet feeder can easily be piped in place in your effluent channel and provide efficient disinfection at an affordable price. These tablet feeders are also available for use with dechlorination tablets.
      If you want to use liquid sodium hypochlorite, we can help you size a pump and chemical storage tank that’s right for your application. Another option is ultraviolet disinfection. This option is a very affordable means of providing highly efficient disinfection. The biggest cost is in the initial investment. But these systems quickly pay for themselves by reducing the man-hours required in operating and maintenance. USABlueBook offers systems that have a lamp warranty of 10,000 hours. These lamps use about as much power as the lamp in your living room.
      As you can see, USABlueBook can help you with most of the available disinfection options. We recommend that you talk with your local regulatory agency when considering any of these options.
  • Why won‘t my chemical feed diaphragm pump the chemical?
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    • There could be a number of reasons why a chemical feed pump will not pump. First thing to do is consult the trouble shooting guide in our catalog as well as your pumps manual where you will find helpful hints on what to check for.
      There are two basic things a pump of this type need for proper operation. First, it has to be able to pull the chemical into the diaphragm housing and second it has to be able to push it out to the injection point. When troubleshooting the cause of the pump failure, you will want to start at the suction side of the pump first. Verify that the foot valve (if your pump has one) which is in you solution tank, is clean and clear of any debris. The foot valve will need to remain in a vertical position in order for the internal check valve to function correctly. Next, inspect the suction tubing and connections for leaks or cracks. A leak on the suction side of your pump may be hard to see and all fittings should only be hand tight, never use a wrench to tighten a fitting as this may distort the seal which will interfere with the function of the check valves and may even create a leak. Check for leaks around the diaphragm housing, most manufactures have incorporated a weep hole in the housing to detect a diaphragm failure, if your pump is leaking from this weep hole, remove the pump from service immediately, consult your owners manual and make the necessary repairs.
      Next, check the discharge side of the pump for leaks. Again, verify the connections haven‘t been over tightened and that the seals haven‘t been distorted or smashed down too far. The discharge tubing and injection valve should be checked next. Inspect for crimped tubing that could prevent the chemical from reaching the injection point. If your pump came with an injection valve, it is recommended that it be installed on the underside of a horizontal pipe between the 6 and 9 o’clock position. Space limitations and accessibility will play a big role in your injection valve location. Check the injection valve for debris or any other obstructions that could interfere with the function of the check ball and spring. Last, verify that the pressure in your line you are injecting into does not exceed the maximum pressure capacity of your pump.
      Some chemicals have a natural tendency to off gas. This off gassing causes air gaps in the tubing and can make its way up into your pumps head and cause your pump to lose its prime. A bleed valve with degassing capabilities is recommended. This degassing valve mounts on the discharge side of the pump and allows any gas to escape with a small amount of chemical back to the solution tank. Depending on the brand of your pump, a knob or adjustment screw is adjusted to achieve this condition. This constant priming should bleed off any gasses in the tubing and pump head. If any of these helpful hints do not fix the problem, the problem could be with the drive end of your pump and may need further technical assistance. Contact our Technical Support Staff and we will be happy to assist you.
  • Can I put chlorination and dechlorination tablets in the same tablet feeder?
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    • No. Using the same tablet feeder for both chlorination and dechlorination tablets can result in a dangerous chemical reaction. If your system requires both chlorination and dechlorination tablets, they must be housed in separate units. Typically these units are separated which allows for some retention time for the chlorine to properly disinfect the effluent wastewater. When the treated water contacts the dechlorination tablets, the reaction is instant and therefore retention time is not as critical.
  • What is the advantage of flooded suction over lift suction?
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    • When pumping gaseous chemicals such as sodium hypochlorite (bleach) or hydrogen peroxide using a flooded suction type application will virtually eliminate the need for repriming. As the chemical off gasses the gas rise’s to the top of the tank and only liquid is fed to the pump via gravity. If your pump has a degassing valve you will want to make sure that this function is not used as the chemical would continuously exit the bleed port. Flooded suction applications are not recommended for use with degassing head type pumps.
  • How do I clean my chemical feed pump?
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    • Note: Please wear proper protective equipment when handling hazardous chemicals.
      Wash the pump, tubing and fittings out with clean water. To do this, place the “suction tubing” and “discharge tubing” (injection fitting too) in a container full of clean water.
      Let the pump run in the clean water for a couple of minutes to remove and neutralize all traces of the chemical you are pumping.
      Remove the mineral deposits. To do this, place the “suction tubing” and “discharge tubing” in a container full of undiluted vinegar or USABB #61147 Calcium, Lime and Rust remover.
      Let the pump run in the solution for 5 to 10 minutes (longer if needed) and let it soak for 1-2 hours.
      Flush out your pump, tubing and fittings to remove any excess vinegar. To do this, repeat steps 1 and 2.
  • When I order a chemical feed pump, what comes with it?
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    • An Instruction manual is supplied with every pump. Most pumps also come with tubing, ceramic weight, injection valve and a foot valve. Pumps with pulse and 4-20 capabilities also come with a connector for input control. Pumps supplied with NPT fittings do not include tubing, weight, or either valve.
  • What is the maximum suction lift for a chemical feed pump?
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    • In most cases, 5 feet for a diaphragm type pump and 25 feet for a peristaltic type pump. High viscosity diaphragm type pumps have a maximum lift of 3.5 feet, however, flooded suction is recommended for viscous chemicals or chemicals that off-gas readily.
  • How do I choose a chemical feed pump for my application?
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    • The following is a basic list of information you will need to provide when you are looking to purchase a chemical feed pump:
      Chemical compatibility: What chemical are you pumping?
      Output requirements; How many gallons of chemical will you be pumping per day?
      Discharge pressure: How much pressure is in the line you will be injecting into?
      Control options: How will the pump be controlled? Manually? Pulse or 4-20 mA signal?
      Voltage required: Do you need 120VAC or 220VAC?