Alarm for excessive water flow?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by mliu, Jan 9, 2012.

  1. mliu

    mliu Member

    Messages:
    101
    Location:
    California
    We have an industrial property that includes an industrial park, as well as three homes for on-site personnel. The water for the homes and some of the industrial facilities comes from the same service line. The back-flow valve is at the street and is plumbed with copper, but transitions to schedule 40 PVC just below ground. That PVC pipe is quite long (several hundred feet) and passes below roadways and over a creek before it gets to the developed area of the property. This service line then splits into several other service branches after that point with various shut-offs, manifolds, and "Y"s. Each branch is a long run in schedule 40 PVC buried under soil and, in some places, under asphalt. Unfortunately, this property was developed in increments over many years by various owners, so the plumbing is far from ideal. But it would be very expensive to retrench and re-pipe the service lines.

    In the past year, we've had five service line failures. Some have occurred in the primary run from the street to the boundaries of the development. Others have occurred in the branches within the industrial park. The break is usually discovered when someone opens a faucet or spigot and discovers there's no water. So by the time the water loss is reported, thousands of gallons of water are lost. Obviously, we need a way to identify the problem and respond faster.

    One thought is to use something called a "Leak Defense System", manufactured by Sentinel Hydrosolutions. This device senses if water flows continuously for longer than a programmable period of time. If so, it automatically sounds an alarm and commands a valve to shut off the flow of water. Two problems with this approach are:

    1. The device requires 120VAC power, which means running conduit all the way out to the street (if we wish to protect the entire main). If we're going to trench and run electrical conduit, it may be comparable in cost to trenching and re-plumbing the main water line with something like PE or schedule 80 PVC.

    2. The homes on the property have fire sprinkler systems that are supplied by the same service line. The instructions form the "Leak Defense System" specify to place the device after the fire sprinkler shot-off valve. I spoke with a gentleman from the company that manufactures the Leak Defense System and he proposed that one of their engineers may be able to come up with a work-around so that the valve is commanded to open (and presumably, to remain open) if a fire alarm were triggered, but it seems like a huge liability risk to me.

    I think a better solution may be a device that simply monitors flow (like the "Leak Defense System") and signals an alarm if flow exceeds programmed settings. I imagine something like that could be created by modifying a Leak Defense System to disable the valve (resolving problem #2), but it would still be dependent on 120VAC power. Ideally, we could find a flow alarm that is battery-powered with a wireless alarm signal.

    Any recommendations?
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    I imagine the building code, and certainly common sense, would prohibit installing anything in front of the fire sprinkler system.
  3. mliu

    mliu Member

    Messages:
    101
    Location:
    California
    I agree, which is why I am seeking another solution. But management is pushing for the use of the Leak Defense System in light of the staggering water bill they just received due to the recent line breakages. In the words of one manager: "Over the years, I've seen many water leaks, but I've never seen a single fire."

    It will be easier for me to convince them that it's a bad idea if I can present a viable alternative.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,247
    Location:
    Cave Creek, Arizona
    As long as whatever you use does not interfere with the flow of the water, and just monitors it, there would be no problem with the fire systems. Conduit can be installed in a very narrow, fairly shallow trench, sometimes with a "slitter", so it would not be comparable to a new water system.
Similar Threads: Alarm excessive
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & Sewage alarm system Mar 15, 2012
Plumbing Forum, Professional & DIY Advice, Tips & Leak detection alarm Jul 16, 2011
Plumbing Forum, Professional & DIY Advice, Tips & New Septic Dosing Tank: Pump, Float and Alarm System Advice Jul 11, 2011
Plumbing Forum, Professional & DIY Advice, Tips & Sump pump alarm recommendations Mar 24, 2011
Plumbing Forum, Professional & DIY Advice, Tips & Overhead sewer maintenance/alarms Nov 5, 2008

Share This Page