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flow rate

In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, rate of fluid flow, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol Q (sometimes V̇). The SI unit is cubic metres per second (m3/s). Another unit used is standard cubic centimetres per minute (SCCM).
In hydrometry, it is known as discharge.
In US customary units and imperial units, volumetric flow rate is often expressed as cubic feet per second (ft3/s) or gallons per minute (either US or imperial definitions).
In oceanography, the sverdrup (symbol: Sv, not to be confused with the sievert) is a non-SI metric unit of flow, with 1 Sv equal to 1 million cubic metres per second (260,000,000 US gal/s); it is equivalent to the SI derived unit cubic hectometer per second (symbol: hm3/s or hm3⋅s−1). Named after Harald Sverdrup, it is used almost exclusively in oceanography to measure the volumetric rate of transport of ocean currents.
Volumetric flow rate should not be confused with volumetric flux, as defined by Darcy's law and represented by the symbol q, with units of m3/(m2·s), that is, m·s−1. The integration of a flux over an area gives the volumetric flow rate.

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  1. M

    Can water flow rate be measured at the supply pipework?

    Hello Guys I recently posted a thread about low water pressure at taps in a new kitchen installed by a company using sub-contractors. I have 0.44 bar of hot water pressure and am getting a flow rate of 4.5 Lpm at the new hot monobloc. The Blanco people say that the taps are rated at minimum 0.3...
  2. M

    Flow rate new kitchen install.

    Hello again Guys I've just had a new kitchen install. The fitters tapped into the overhead 15mm hot and cold that feeds the Utility Room 3.0m further on. The hot flow rate in the Utility Room (Monobloc taps) is 9.5 litres/min. In the new kitchen monobloc the flow rate is 4.5 litres/min, less...
  3. K

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  4. R

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  5. B

    Water flow rate bathtub query

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  6. MrGatch

    Central Heating Flow Rate (Rads+UFH)

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  7. A

    HOW TO INCREASE FLOW RATE & PRESSURE 3 BED SEMI

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  8. P

    Combi KW Rating (High or low?) - Fit De-aerator and Extra Expansion Vessel?

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  9. O

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  10. G

    Vaillant ecoTEC Plus 938 - Low Flow Rate

    Hi guys. Hope you are able to help me, and thank you in advance for anyone who can contribute. I've got a Vaillant 938 and notice that the hot water output isn't near the claimed flow. I've tested the pressure at the stopcock and it's around 3 bar. I've tested the cold flow rate from the...
  11. R

    Does air lock affect flow rate in UFH

    Hi all, having issues with my underfloor heating . Flow doesn’t stay hot as return just stays cold even though boiler is operating as it should . My question is does an airlock reduce the flow rates ? I can get good flow 4+ ltr / min through the loops but still the return and hence flow stays...
  12. M

    Thermal store combi boiler, hot water flow rate.

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  13. T

    HIU Flow Rate Dropping

    Hi All I live in a new build block of flats. We all have HIUs. This model. Type 2 HIU Connection for Primary & Secondary Heating Circuits - Switch2 - https://www.switch2.co.uk/product/type-2 The entity that owns the system didnt maintain it very well so they just had to flush the whole...
  14. R

    Flow rate on Intergas Boiler

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  15. M

    Drainage flow rate calculation

    I have been asked what the flow rate of the drainage is on a project we are doing of 23 flats. I’ve never had to do this before, can anyone advise on how this is done?
  16. L

    low flow rate, undecided on options.

    Hi I have an old property with a Low flow rate coming in from Mains. Old black imperial pipe from a long run. This is not a simple job to replace so looking for other options. It currently has 5 bar on standing but drops off as soon as one tap or shower is used. <1 bar. The property is being...
  17. J

    Higher Flow rate required

    Hi there, I'm away to first fix 3 x 1 bedroom flats. There is is One Cold supply in basement below flats, the pressure/flow rate isn't great. Without getting council to Install a bigger service is it possible to install a pump or Cold main booster to give adequate flow rate to these...
  18. J

    Higher Flow rate needed

    Hi there, I am about 1st fix 3 x 1 bedroom flats, small 15 litre water heaters under basins and sinks. Electric showers. Problem is there is One 25mm (poly) cold feed with low pressure. Without involving Council for Larger supply to property is it possible to install a suitable pump...
  19. gmartine

    Combi installation, mixer valve on HW outlet & CW inlet to improve flow rate?

    CW inlet...about 15 minutes in, seems like a good idea.
  20. A

    Version boiler flow rate.

    I have decided to go for the Version boiler when I get my system upgraded but I currently have a Glowworm 35 store which gives lashings off hot water which ilike, so I'm looking at the 111-w as its the same performance as the glow worm, I did initially go for the 100w button I was a bit...
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