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Remove Restrictions Only Where Needed

The conventional wisdom for collections is – "If you can afford it, clean everything on a timed basis whether it needs it or not." The QFlow technique takes a different approach. QFlow simplifies calculating the hydraulic performance of your collection system so that it is possible to identify and prioritize portions of your system needing preventative maintenance, inspection analysis and repair.

QFlow is a patented method of evaluating a gravity-flow collection system based on comparing and contrasting the actual flow depth from within a pipe section against a calculated flow depth. The goal of preventative maintenance is to clean only the sanitary sewer lines with deficient conveyance capacity and not waste time and manpower on lines that are performing properly. This process provides an uncomplicated tool to isolate potential blockages, debris, root infestation, groundwater infiltration or hydraulically defective sections of pipe. Once flow depths are collected at each manhole, the "QRatio" is determined to estimate the reserve conveyance capacity within the pipe network.

The QFlow process begins with the identification of all data collection points (manholes) from accurate, system-wide collection system maps. For each of these points the anticipated flow under standard and normal conditions is calculated, based on the number and type of customers upstream from each access point (manhole) as well as the diameter of the downstream pipe.

The actual flow is then measured at each asset location (manhole) using a paper depth gauge attached to a stick. Our software database program then uses a built-in calculation based on the pipe geometry and the number of gallons generated upstream of each access point. The estimated gallons are converted to a flow chart, that is then converted to a flow depth; which is then compared to the actual measured flow to create what is called a "QRatio."

Using the database selection process, the QRatio of all access points in the system is ranked and the nearby pipe segments prioritized for inspection and maintenance. If the "QRatio" is significantly higher (greater than 2.0), the pipe segment immediately downstream of the access point is selected for cleaning and video camera inspection.

Although less precise than more complex and expensive monitoring systems, this economical process allows small and medium-sized sanitary sewer utilities the ability to regularly survey the performance of their entire system. While limited resources are not wasted analyzing, testing, or monitoring the entire system, rapid response to debris, obstructions and hydraulic defects can still be found in a preventive manner when utilizing the QFlow process. Restoring the conveyance capacity of the collection system will also lessen the potential for sanitary overflows and basement flooding.

QFlow specialized paper for measuring data

Specialized QStik paper compared to standard paper

QFlow specialized paper for measuring data

An added benefit of QFlow is the ability to prove that the cleaning process actually clears the obstructions. Too often, a jetter company is contracted to remove debris in sewer lines and unfortunately the debris is simply displaced and not vacuumed away. A simple "before and after" depth test assures that the job was done correctly.

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For more information on QFlow contact us.