hose pipe diameter: which to choose?

[Stephen]

Hello,

I need to buy a hose pipe that will reach from the patio, across the lawn, to the driveway behind it. I think it is about 30 metres, so plus some room to manouvre, I think I will be looking at a 50m hose pipe. I need it to wash the car and also to try and clean an oil spill off the paving!

I was going to go with something like this:

which is not supposed to twist or kink, but I also saw this:

which according to the reviews, can kink, but it is 3/4" diameter rather than 1/2".

Which would you buy?

I am wondering whether the 3/4" is better, particularly for long lengths, as it might have a greater flow and less internal resistance?

Thanks, Stephen.

[Jonno]

Stephen scribbled

If the internal diameter of the hose is greater than the internal diameter of the pipe supplying the water....

[Dave Plowman (News)]

'30 yards of hosepipe, please.'

'Sorry sir - we went metric years ago.'

'Ok - give me 28 metres'

'Certainly sir. 1/2" or 3/4"?'

[harry]

3/4" hose will obviously deliver more water than 1/2" But the pipe you are connecting it to s probably only 1/2". So in practice will make little difference.

[Adam Funk]

Good one.

[Kevin]

Go one... I can't quite see where this is leading.

[Tim Lamb]

More seriously, what would be the flow rate through 300m of 20mm mdpe equating to a 1 bar pressure loss?

>

[harry]

[Tim Lamb]

In message , harry writes

Ah! The d-i-y kit. Pity they are all .com sites.

However, it appears that a flow of 1 gallon/minute equates to a head loss of 1.05m per 100m of 13mm pipe. American gallon?

[www.GymRatZ.co.uk]

But it will make a difference as the flow loss will be greater over 30M

1/2" than 3/4" so surely the answer depends on the required flow rate. If it's just to splash some grass and flowers or spray the car then I'd go for the easiest pipe to store but if it's to feed a pressure washer on a daily basis bigger is best.

When the water man came out to advise me on running a new pipe from the street meter I queried whether there was much point running it in 32mm rather than 25mm when I was still going to be connecting up to a few inches of black pipe from the meter. His answer was a resounding "Yes" and he explained that they only used a

15mm (I think it was) spur to connect 60mm pipe to the water main because anything bigger created a significant weakness in the water-main pipe.

FWIW

[Stephen]

Thanks. It seems obvious now that everyone has mentioned it that it will be supplied by 15mm copper pipe. I suppose I was thinking that there would be more resistance in the hose pipe than the copper pipe feeding it because the hose would be longer and would have more bends in. I guess I'll get the good quality 1/2" pipe rather than the cheaper 3/4".

Thanks, Stephen.

[Terry Casey]

Reminds me of getting some 19mm chipboard cut to size for a loudspeaker baffle about 30 years or so ago.

I wanted two pieces 550 x 330 but took the precaution of converting these measurements to imperial, as well.

I went the shop and was asked the dimensions. "Metric or imperial?" I asked.

With a look of relief on his face, back came the reply "Imperial, please."

I quoted my imperial dimensions, ending with "... by three-quarters."

"Oh, it will have to be 19mm, it's all metric now!"

He really couldn't work out why I burst out laughing ...