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flow and return

Return flow is surface and subsurface water that leaves the field following application of irrigation water. While irrigation return flows are point sources, in the United States they are expressly exempted from discharge permit requirements under the Clean Water Act.Return flows generally return to the irrigation centre after a period of about three to four weeks; due to this, the farmers usually need to pour bleach into the water to clean it of any organisms that have entered the stream. If this is not taken care of, diseases such as typhoid or cholera could enter the irrigation and pose a risk of epidemic disease to surrounding towns and cities.
The return flows in irrigation is nearly 50% of the water supplied in silty clay soil type in tropical countries. The salinity of the return flow water increases with decrease in % of return flow quantity. Rest of the water supplied to irrigation evaporates to atmosphere due to evapotranspiration.
When ground water is extracted for irrigation and other uses, most of the return flows seep back into the ground instead of joining the nearby surface stream. When ground water is used in excess of recharge from rainfall/precipitation, the quality of groundwater deteriorates over a period of time and becomes unfit for irrigation use.

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  1. T

    w/c pan fixing points directly over c/h 22mm flow and return pipes.

    The subject line says it all! The new close coupled pan/cistern I have to fit has its fixing holes directly over the main 22mm c/h pipes. I'd have to pack the cistern off by about 30 mm. to clear the pipes. I'll fix with some short screws that don't penetrate the flooring but what else can I do...
  2. F

    New boiler flow and return temps

    Hi all, Just had my new boiler installed. Went from a heat only with hot tank to a combi boiler. Its a Ideal Logic+ 30 and in the menu it shows sensor values. I understand there should be a large difference between flow and return values but quite often when running there is only a 5 degree...
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  3. M

    Flow and return pipes

    The flow and return pipes on a CH system, is it usual to have the flow split off into two, i.e. one branch going off upstairs and the other continuing downstairs? Likewise with the return merging into one back to the boiler in a "T" shaped connection, i.e. the return from upstairs and the return...
  4. P

    Using plastic pipe on flow and return

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  5. K

    Flow and return pipes

    Hi, Im currently replacing the central heating system in our house and have the following question. Our house has solid floors downstairs so both the upstairs and downstairs radiators will be supplied from 22mm flow and return pipes routed between the upstairs floorboards and downstairs...
  6. U

    Radiator with combined flow and return

    Hi, I'm trying to to remove a radiator with combined flow and return valve (at same end of radiator) Have managed to bleed the radiator but having trouble removing it due to the pipe that runs the length of the inside of the radiator? Do I simply cut the tube to remove the rad? Don't want to cut...
  7. A

    Flow and return issues

    Hi guys, Ive been registered on here for a while and never really used the service but it looks like many minds are better than 1. I have a property with 6 rads and 1 cylinder s plan system boiler the upstairs rads have issues. Nannys room - TRV shut off the return pipe gets hot, when the TRV...
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  8. Riley

    Working out flow and return

    Right I know this is a Mickey mouse question but I've wasted enough time on it today. Trying to re-pipe a number of rads for a customer but their flow and returns are all over the place some left some right on existing rads new rads are very specific in that flow must be left and return must...
  9. D

    Radiator flow and return question

    Hi - a quick question hopefully someone can answer... In summary I wish to install a large radiator in my downstairs kitchen, which currently doesn’t have one. For reasons I won’t go into, the flow and return pipes downstairs are a royal pain to get access to. However, in a room above the...
  10. B

    Flow and return temperature

    Hello all, Is there and ideal temperature that shout be set for dhw and heating?
  11. R

    Condensing bolier flow and return temps - effect on rad sizing?

    Had a quote for complete new CH system including Worcester Greenstar 28i Junior. Not sure I totally understand this, hence asking here: I was pretty surprised at how small the rads spec'd were as I thought condensing boilers needed as low a return temp as possible? The installer (WB...
  12. M

    Bypass on primary flow and return to indirect cylinder

    Hi if fitting a bypass on the primary flow and return to an indirect hot water cylinder I know this needs to be positioned between the pump and zone valves as once the zone valve shuts off the pump will have an over run. Is this correct? Also do people now fit automatic bypasses instead of a...
  13. C

    Gravity flow and return from wood burning stove to thermal store ??

    Hi i would like some other plumbers advice who have had good experience with solid fuel and gravity installations. I have just fitted a 300 litre thermal store in a customers new house. The thermal store is upstairs in the hot press and the wood burner downstairs. This house however has...
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  14. B

    Flow and return - swapping connection...

    Hi all, Apologies if this seems like a silly question. Does it matter if you swap the return and flow connection? Will the heating work as it should?
  15. S

    flow and return of a solid fuel stove

    Hi First post so go easy I'm fitting a solid fuel linked up system (eventually) in my home . I've done this a few time in various houses over the years but never before in a bungalow . In a house i 've always gone up with the pipework from the rear of the boiler . Years ago when i last...
  16. B

    Airlocks in boiler primary flow and return??

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  17. C

    New Combi Boiler - Flow and Return Pipes

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  18. L

    Flow and return pipe sizes?

    Hi all Had to move a magnaclean from above the boiler to the cylinder cupboard today (magna clean was 28mm reduced to 22mm right next to the boiler) and the primary flow returns was in 28 mm in the cylinder cupboard. the chap that i work for said that I would have to step the magna clean back...
  19. C

    Flow and return

    Is it possible that my old boiler (baxi solo 2 40pf ) had been wrongly connected to flow and return after being moved , it still worked , slower heating up and after a while the boiler kept overheating and shooting up to header tank.
  20. D

    flow and return pipes

    Should the flow and return pipes on my radiators be of the same temperature when the boiler is fired up? The reason I ask is because one pipe on the rad is really hot and the other is warm and the same on another rad in the same room. is this normal? cheers
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