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lemanj48
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Join Date: Jun 2008
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Diff Press Via Flowrate

01/18/2011 8:27 AM

Hi, I need help. How to calculate the Flow rate of chilled water in the closed pipe from the pressure different reading between air handling unit? Anybody can give respond on their opinion and experience are much appreciated. Regards, Sulaiman.
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PWSlack
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#1

Re: Diff Press Via Flowrate

01/18/2011 9:23 AM

Calculate?

Just add a clamp-on ultrasonic flowmeter to the pipe and measure it.

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Anonymous Poster
#2

Re: Diff Press Via Flowrate

01/18/2011 11:01 AM

Hi

usually the standard speed(S) for pipe is 1.5 m/s.

you could be able measure the surface area of pipe(A).

And use this formula Q=A*S.

Where Q= flow rate(m3/s)

A= Surface area of pipe.

S=1.5 m/s
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Doorman
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#4
In reply to #2

Re: Diff Press Via Flowrate

01/18/2011 2:53 PM

I believe you may have misread the directions included with your LynDoor™ Industries Bridge Data Generator. You have neglected to filter the data thru the single slice of sandwich meat as directed. Thus, your response contains excess baloney.

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lyn
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#3

Re: Diff Press Via Flowrate

01/18/2011 2:08 PM

Consult this web site www.engineeringtoolbox.com/chilled-water-d_955.html and ignore Post #2 from misguided guest.
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LAA_Lucke
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#8
In reply to #3

Re: Diff Press Via Flowrate

01/19/2011 7:40 PM

Knowing only the differential pressure accross an air handling coil is not enough to enable the calculation of the flow rate in that coil. You need to have the manufacturer's flow curve for that coil giving you the flow rate against the pressure...
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PWSlack
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#9
In reply to #8

Re: Diff Press Via Flowrate

09/05/2024 3:44 AM

One also needs to know the extent of internal fouling that has taken place.

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ellururamaiah
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#5

Re: Diff Press Via Flowrate

01/19/2011 3:11 AM

Dear sir,

you have to incorporate flange joint with orifice in straight line of the chilled water circuit,then it is very easy to calculate the chilled water flow in the system by measuring the pressure drop across the orifice.

ELLURU RAMAIAH.
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enervac
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Join Date: Jun 2010
Location: Chennai India
Posts: 20
#6

Re: Diff Press Via Flowrate

01/19/2011 3:25 AM

You should get the Flow rate versus pressure drop across the Cooling coil /Condenser.Then by measuring the pressure drop you can determine whether adequate flow is there or not. You can adjust approximately closer to the differential pressure required by opening /closing outlet valve to the extent required.

This method is not accurate but better than not measuring at all. Exact quantity of flow can be established by using Ultrasonic flow meter and adjust the valve to ensure flow is closer to the requirement.

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Ducdude
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#7

Re: Diff Press Via Flowrate

01/19/2011 10:13 AM

+1 for a Clamp on Ultrasonic flow meter....Some can be had for $2-3K and are easyly relocateable....Acc will be 1-2% of rate.....

Many vendors offer them..

Eric
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PWSlack
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#10
In reply to #7

Re: Diff Press Via Flowrate

09/05/2024 3:45 AM

They can also be hired.

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Users who posted comments:

Anonymous Poster (1); Doorman (1); Ducdude (1); ellururamaiah (1); enervac (1); LAA_Lucke (1); lyn (1); PWSlack (3)

Previous in Forum: Wafer Lug Type Butterfly Valve - Tapped or Through Hole to Be Used at Flange   Next in Forum: Pressure Vessel - Hydrostatic Test

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