Flow Rate and Pressure in Parallel Pipe System

Should work...

http://www.1728.org/flowrate.htm

Yeah, plumbers don't come cheap...

Exactly. It sounds as though the design, as it stands, is inadequate.

Nope, that's a bias data gathering.

Try another scheme of sensing that should not even influence the flow. What type of transducer are you using?

It's flawed. Pressure drop down pipes is not a linear function of diameter when the Reynolds Number is above 2100 or so, and yours is above that. Plus, although the top rating is stated, no one here knows what the maximum pressure is that your pump is capable of producing.

Thank u all for the inputs and answers.

1. As per theoretical calculations, the 1.5hp pump will generate around 300+ litres/ min at 75% efficiency.

2. In long term can order a higher limit sensor but at the moment it shows 3-4 weeks to deliver to my region from China and i cant find it locally. The project demo is in 12 days time so cannot take the risk, hence the work around with the split pipe mechanism.

3. Fortunately the plumber is free as my partner's dad owns a real estate company and have plumbers available.

4.@gutmonarch - not using transducers but rather this sensor with higher limit.

http://www.electroschematics.com/12145/working-with-water-flow-sensors-arduino/

I am going to try the setuo advised by you guys and update the findings.

Thanks RJ

Oh, thats a positve displacement type flow meter. I just dont know exactly whats your set up. It is a big no to measurements if you make it to represent the whole flow with that parallel pipe configuration. Except if it pass the criterion basing on reliability and precision with some stat tools.

Anything that converts process variables to other communication signal to a processing module is a tranducer.

You better be posting your set up. Picture paints thousand words.

Why not make a semi- flexible bend and attach a strain gauge then analyse signal using Adruino. That's best non-invasive solution.

Thanks Tornado for the reply. This is exactly how I am trying out the test setup. Will update you on the results shortly.

I might have a question of the Darcy Friction Factor and as to how to calculate it accurately. Can you shed some thoughts on that?

Thanks RJ

Darcy-Weisbach calcs are usually done in conjunction with a Moody chart. A pipe design text or Wiki articles will do better justice to this than I can do. (Unless I just copy stuff....)

Why don't you go with an industrial water flow meter that is relatively cheap (Signet, or other brand), and use the 4-20 mA output as analog input over a pull-up resistor as analog voltage in? These sensors (and their associated transmitters) allow programming the K value of the sensor associated with the correct pipe diameter in the first place, and are available down to fairly small pipe diameters, of at least as small as 12 mm. You have also the option of making the local pipe large at the sensor such as 30-50 mm, and programming in the K value for that pipe.

It is not rocket science or every industrial plant (including the ones I work at) would have to hire NASA every time we installed a new flow meter.

I agree that this ad hoc calibration might be best for him in the long run, since he has already most of the equipment for that.