Backflow prevention for water powered sump pumps

Backflow Prevention

Basepump

"Ask for it by name"

Backflow Prevention

  • Backflow is a term used in the plumbing industry for an unwanted flow of water in the reverse direction. It can be a serious health risk for the contamination of potable water supplies with foul water.
  • A water powered sump pump has a point where the clean "city" water and the dirty sump water meet. This is considered a "cross-connection" and during a backflow event, sump water could be pulled backward into the potable water supply.
  • The standard Basepump design incorporates a control valve that is in the closed position until activated by a float in the sump.
  • At any time that the ejector is not operating, the control valve at the pressurized potable water supply is closed, the suction pipe is empty, and the discharge pipe should also be empty as a typical installation should have it open to the atmosphere on the exterior.
  • During normal operation, the pressurized, potable water is in a forward-flowing, "positive pressure" condition.
  • If the potable water supply loses its pressure during pump operation and actually pulls into "reverse" causing a "negative pressure" condition, it is possible for sump water to be siphoned back into the potable water supply pipe.
  • Because this can only happen during a pumping cycle, the likelihood of such an occurrence is extremely remote. Each Basepump is designed to minimize this risk, but most authorities require that an "approved" backflow prevention device be added to a Basepump installation to protect the potable drinking water supply.
  • So we don't just talk about it, we make them available. See them here below:

Click here for a Backflow Information Sheet:

Backflow Prevention Sheet Thumbnail

Backflow Prevention Devices for RB750 and HB1000:

1. Dual Check Valve

Basepump Ejector showing Highlighted Dual Check Valve connected 
  • The standard Dual Check Valve is a generally accepted backflow prevention device and we have them available in 3/4" size. (1/2" available only until stock runs out.)
  • Installation of a standard dual check valve into the potable water supply piping prior to its entry into the pump prevents water from flowing in the opposite direction.
  • This brass device contains two internal check valves for redundancy, or a "fail-safe" condition. This allows water to flow through it in only one direction.
Dual Check Valve Standard

Standard Brass Dual Check Valve

  • Installer inserts this into the water supply pipe that feeds water to the pump.
  • Depending on the water pressure, the use of this check valve may reduce the pumping volume slightly.
  • Meets ASSE listed #1024, CSA  Certified B64.6
  • Dual Check Valve Model:

    • DCV-¾" $26.00

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2. Dual Check Valve with Vent (State of Illinois Approved)

    • Dual Check Valve with Vacuum Breaker Vent (3/4" only).
      Basepump faded with enhanced DCV VB
    • Installation of the dual check valve with vacuum breaker vent does the same job as the standard dual check valve, but has the added feature of a vacuum breaker, downstream vent.
    • This type of Dual Check Valve also contains two internal check valves that only allow water to flow through it in one direction.
    • Downstream vented vacuum breaker gives added protection as required in some jurisdictions.
    • Depending on the water pressure, the use of this check valve may reduce the pumping volume slightly.
Dual Check Valve with Vent 04 2016

Dual Check Valve with

Vacuum Breaker Vent

    • Meets ASSE  listed #1012, CSA Certified B64.3
    • State of Illinois Approval #890-1140(k)
    • Dual Check Valve with Vacuum Breaker Model: 

      • DCV-VB-¾"  $39.00

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3. Atmospheric Vacuum Breaker (AVB) Valve (State of Wisconsin Approved)

BasePump AVB Unit shown installed and highlighted on a standard Ejector.
  • Many municipalities recognize an Atmospheric Vacuum Breaker (AVB) as an effective means of preventing back-flow in certain cases. 
  • In the unlikely event that the potable water supply loses its pressure during a pumping cycle, and actually pulls into "reverse" causing a "negative pressure" situation, the AVB immediately opens to atmosphere, which effectively prevents a siphon.
  • Basepump is able to use this device because of its location on the ceiling, giving it the necessary height to prevent water from backing into the potable water supply. 
Standard AVB Valve only on White Background

Atmospheric Vacuum

Breaker (AVB) Valve

  • Install AVB valve at least 6" above the next highest point of discharge. The configuration of the pump provides this 6" rise and the discharge must continue on a level or downward pitch to the exterior so as to self-drain when the pump shuts off.
  • Note: If the discharge rises above the pump to the exterior, the AVB valve will spill the remaining water back into the basement after shut-off. It is an open air vent.
  • Do not connect the discharge from the Basepump into the discharge from the primary sump pump when using the AVB Valve. It will cause the primary pump to send water back to the Basepump each time it runs and it will spill from the open Vacuum Breaker.
  • The 3/4" unit, as shown above, is an "add-on" to Models RB750 and HB1000. Installer must insert this unit into the ejector according to directions sent with the unit.
  • If it is purchased with the pump and then later the installer determines that it won't fit the application, you may return it for a refund.
      • Meets ASSE listed #1001, CSA 64.1.1 Certified, IAPMO Listed.
      • State of Wisconsin Approval# 20100389
      • State of Minnesota Approval# 603.5.9
      • State of Ohio Approval# 608.3
      • State of Indiana Approval# 608.3

Atmospheric Vacuum Breaker Model:

      • AVB 3/4" $36.00

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4. Reduced Pressure Zone (RPZ) Valve (Multi-State Approved)

Reduced Pressure Zone (RPZ) Backflow Prevention Valve
      • Reduced Pressure Zone (RPZ) Valve prevents the reverse flow of polluted water from entering into the potable water supply due to back-siphon and or back-pressure. The RPZ comes assembled with two 3/4" Ball Valves, as shown here.
      • This device will restrict water flow more than the other two options, and in some cases may prevent a water powered system from operating, in cases where the water pressure is low.
      • The most costly choice of the three we offer, in some cases, it may require an annual inspection by a certified technician. 
      • This type of device is sometimes installed at point of use, such as a sprinkler system, but is usually installed at the main inlet to the home.
      • We show it here by itself because it can be installed in either the dedicated water line to the Basepump or on the main service line to the home.
      • It must be installed in a horizontal position and it is best to keep it low enough to service properly, i.e. waist-high.
      • Always check with your local plumbing department if you have any questions.
      • Depending on the water pressure, the use of this check valve will reduce the pumping volume slightly.
      • The RPZ is nationally approved and accepted by all municipalities.
      • Meets ASSE listed #1013, CSA Certified.

Reduced Pressure Zone Model:

      • RPZ 3/4" $179.00

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