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Backwater Valves Frequently Asked Questions

  1. Can a Smith backwater valve (BWVs) be installed in a pressurized line?
    No, Smith backwater valves are designed for gravity fed drainage lines only.

  2. What types of Smith vertically installed backwater valves are available for floor drain applications?
    Figure 7080 BWV is a ball float BWV designed to connect to a vertical outlet floor drain. There are flapper and ball float BWV’s available for figures 2005 and 2010 adjustable floor drains. They are located in the throats of both round and square strainers. Example: AV05NB for a flapper type BWV and ABF05NB for ball float type BWV.

  3. Do flapper & ball type BWV’s provide a 100% positive seal?
    No. The ANSI/ASME national standard allows for a minimal amount of seepage around the flapper or ball. The purpose of a flapper or ball is to suppress the back flow. Therefore, if the back flow condition exists over a lengthy period, there will be water seeping into the building at the lowest fixture or floor drain. For a 100% positive seal, you need to specify a figure number 7140 FloodGate BWV.