Complete hook-ups are available 1/2" through 2". Balancing valves are available through30".

Components are brass, bronze, and copper.

The decision to use factory assembled, compact hook-up products generally rests with the contractor. However, the engineer must still approve specific components such as balancing valves. FDI manual and automatic balancing valves have universal engineering acceptance.

Most Flow Design products are manufactured in Texas. FDI will certify that any of its products will meet the “Buy American Act”

Standard delivery is two weeks (10 days) after Flow Design receives an order. There are also 1 or 3 Day QuickShip programs available. Please contact your representative for fees.

Every FDI assembly is factory tested at 100 psi air under water.

FDI will mount/assemble ATC valves and leak test the valve joints. About 40% of the hook-ups shipped have the ATC valve mounted by FDI. By consigning the ATC valves to FDI the complete hook-up can be shipped in one box.

Five years for Brass, 12 months for Hoses.

AutoFlow only changes the behavior of a modulating ATC at flows above 50% of the AutoFlow value, which corresponds to loads above 75% of the rated maximum output.  AutoFlow has the advantage of removing itself as a restriction if excessive pressure is not present, making it advantageous in variable flow systems.

Please remember that we do not guarantee accuracy outside the control range, but the following is pretty close:

 

Q=Q0*sqrt(DP/DP0)

 

Q is the actual flow

DP is the differential pressure

Q0 is the design flow

DP0 is the maximum of the control range if the pressure is above or the minimum if the pressure is below

 

Example: 5 gpm autoflow with a 2-32 pressure range

@ 1 psi: sqrt(1/2)=0.707 -> Q=5*0.707=3.5

@ 35 psi: sqrt(35/32)=1.046 -> Q=5*1.046=5.2

AutoFlow may be used with any concentration of either Propylene or Ethylene glycol.  The flow rate changes inversely to the square root of the specific gravity.  In other words if the specific gravity of the fluid is 0.94, the flow will be 3% above the marked flow.  Thus for most concentrations of either ethylene or propylene glycol the change of the flow rate is fairly small.

Yes, and the flow can be either up or down.

There would be additional error in the readings. The standard accuracy of ±1% could become ±15% without the proper straight run. If the venturi must be installed anyway, the available straight run should be used on the inlet (upstream) side. The amount of error without proper straight run cannot be predicted.

Flanges allow for easy removal for servicing, but since there is nothing to service on venturis the preferred connection is weld ends.

Yes, as long as it has the proper full scale calibration. 0 to 300” (0-20’) is the most popular combination instrument for measurement and balancing.

Yes. One-half or more of the overall accuracy depends on the readout kit. Whatever meter error is present, adds algebraically to the 1% venturi error. The FDI Meter Kit 300.4 has a full scale accuracy of ±1.75%. In normal use, the error increases to 4% or 6% when metering at ³P’s below full scale.

Yes, individual venturi curves are shipped with each unit.

Yes, individual venturis can be flow tested by the FDI engineering department at a specified flow and certified to ±1/2% accuracy. The cost for this testing ranges between $300 and $600 per venturi.

Yes, FDI's engineering department can give formulae for converting other liquids and gases to standard GPM of water so the flow equations for water can be used.

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