50mm hose

[Blue]

Isn't it 52mm?  :lol:

[bittenyakka]

Um you use it don't you> :?

[Scania_1]

Yes the MFS use 52mm hose, the yellow ones.

[Camo]

That forgetful you need to colour code the hoses?

:lol: :lol: :lol:

[Blue]

I was just being facetious, devil's advocate if you will, pointing out the 2mm discrepancy  :wink:

Don't say just yellow hose if you want 52mm Ath, cos I might bring you some 25mm lay flat instead  :lol:

[Scania_1]

Well you wont find any layflat on our appliances. Only on the white ones..lol.

[Blue]

And the yellow ones  :lol:

[Camo]

Oooohh can we steal the white hose?  It will match our truck!

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

[bittenyakka]

It only stays white until you go to a fire :-P

[Smokey Bear]

You put your finger over the end of a 64mm, 50mm and 38mm hose line and tell me the difference. While your at it take a photo and post it to SAFF.

Your finger may not do much but what about sticking a nozzle on the end of the hose and tell me what that does to the pressure brainiac!

[Hicksflat14]

*Yawn* Its been discussed already. Learn to read, when you get to high school study physics, then come back to the forum with anything you don't understand.

[Smokey Bear]

I started reading it then found it to be a whole heap of dribble so didnt bother continuing.

[SA Firey]

And anyone who uses the term "layflat" doesnt know their terminology for fire hose.Its a slang term which the fire services have adopted

Remember its either percolated or non percolated hose

[Gilly]

Relating to hicks flat's comments on the previous page about flow rates etc.
Re-reading the initial statement about forcing 64mm work of water through 50mm increases pressure is correct. When pumping volume, the larger the hose, the less pressure required for the same volume/flow rate, as hick correctly stated. however what the initial comment meant was that if you had fixed pump pressure and branch flow rate on a 64mm line, and you restricted the flow (ie adding a 50mm working length) the pressure inside the hose would increase if nothing else changed. Same as when you knock off a branch, the pressure inside the hose increases (except on a smaller scale as the restriction in flow is minimal)
To explain in a tangable fashion: (figures are not accurate - demo only)
A 64mm hose has a flow rate of 400GPM at 700kPa
A 50mm hose has a flow rate of 400GPM at 800kPa
A 200mm hose has a flow rate of 1500GPM at 700kPa (if the pump could do it!)
In lay terms, to achieve the same volume: the smaller the hose, the higher the pressure.
to achieve a flow rate of 400GPM in 50mm hose, Pressure would have to be 800kPa.
This is based on a branch with fixed flow rates, non adjustable etc (as in basic, hick)

I am also familiar with fluid mechanics my friend, and by over-complicating a simple issue, you have not only made your self seem like a jerk, but actually shown your stupidy in not being able comprehend the initial meaning of the statement. Brainiac...

[Hicksflat14]

Re-reading the initial statement about forcing 64mm work of water through 50mm increases pressure is correct.

It increases pressure PUMP end, but the poster that kicked this all off believed it increased pressure BRANCH end which it does not. Tillerman confused static and dynamic pressure and the significance that each plays.

however what the initial comment meant was that if you had fixed pump pressure and branch flow rate on a 64mm line, and you restricted the flow (ie adding a 50mm working length) the pressure inside the hose would increase if nothing else changed. Same as when you knock off a branch, the pressure inside the hose increases (except on a smaller scale as the restriction in flow is minimal)

To maintain the flow rate with the 50mm as the second line then the PUMP pressure would need to be increased. The pressure at the end of the 64mm would increase but the pressure at the end of the 50mm (at the branch) would be the same for the same flow rate, not higher as stated by the original post.

In lay terms, to achieve the same volume: the smaller the hose, the higher the pressure.
to achieve a flow rate of 400GPM in 50mm hose, Pressure would have to be 800kPa.
This is based on a branch with fixed flow rates, non adjustable etc (as in basic, hick)

You are perfectly correct there and consistent with my previous posts being that the pressure PUMP end needs to be higher to get the same amount of water out the other end. This however does not result in higher pressure at the BRANCH end for the same volume flow.

I am also familiar with fluid mechanics my friend

Congratulations.... even though you do seem a little lost. Its covered in most science, maths and engineering courses so its not exactly difficult to come across while studying.

you have not only made your self seem like a jerk, but actually shown your stupidy in not being able comprehend the initial meaning of the statement. Brainiac...

well my initial statement was:

"So the hose increases pressure? There I was thinking it was the pump."

And that is still 100% correct. You can have all the hose you want, but the pressure/flow/energy comes from the pump (neglecting gravitational effects).

Next I quote for you what tillerman said:

Well i don't know about you but i thought when you force 64mm worth of water into a 50mm hole the water would have to speed up therefore giving you more pressure at the tip...

I didn't think you could miss comprehend that, but you are from Burnside. If you know fluid dynamics like you say you do, then you should know that statement is incorrect. Pump end pressure increases but "tip" pressure remains the same for the same flow rate.

I put it to you that you have over simplified the problem and not only made your self seem like a jerk, but you've actually shown your stupidity (not to mention miss spelling stupidity) in not being able comprehend the initial meaning of the statement.

[Blue]

And anyone who uses the term "layflat" doesnt know their terminology for fire hose.Its a slang term which the fire services have adopted

Remember its either percolated or non percolated hose

Same as my gripe about the 'Hooligan' tool but everyone still says it SA Firey

[Gilly]

Hick
I agree with your information mate, but did not like the way it was initially delivered. I cannot speak for every one here, but i can hazard a guess to what they thought also.
The comment about the brigade I'm from is a bit unnecessary, and shows a lack of anything else to say.
Thankyou for the tip with the spelling too. I'll try harder in future. I'm still on an "A" though aren't I?  :-)
No hard feelings

[5271rescue]

NSWRFS use 52mm blue hose nice :roll:

[SA Firey]

NSWRFS use 52mm blue hose nice :roll:

They get more money than we do Bill :lol: :-P