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Water hose diameter

benb21601
Explorer
Explorer
just a quick question on using 1/2 inch diameter water hose vs 5/8 inch. i have always used 5/8" but plan on changing around some plumbing and all i can find that will fit my plan is 1/2". curious if anyone has had issues/ no issues with the smaller diameter. not so much worried about pressure as volume. i think all the internal plumbing is 1/2" or smaller so this shouldn't be an issue, hoping for some first hand experience.

Thanks
2017 GMC Sierra 3500 Denali Dually Duramax L5P
2015.5 Jayco Seismic 3902
2015 EZGO Express S4 buggy
17 REPLIES 17

FlatBroke
Explorer II
Explorer II
I would worry more about flexibility. I have 3 Camco hose that are soon to hit the trash. A real pain to roll up when it's cold and even warm they are a PITA.

Hitch Hiker
"08" 29.5 FKTG LS

Lowsuv
Explorer
Explorer
I would not use 1 /2" .
5 /8" is most common and cheapest .
In plumbing and electricity the smallest pipe diameter restricts the flow of the entire run .
As has been pointed out .
In actual practice there is a slight advantage to using 3 /4 if the runs are long .
That should not be true .
But it seems to work that way .
I have a 3 /4 ( expensive ) and a 5 /8 .

benb21601
Explorer
Explorer
Thanks all for the replies. I guess to simplify the original question down- Does anybody use a half inch? I agree that there should be no difference, just wanted to verify before I invest in the hardware. Thanks again.
2017 GMC Sierra 3500 Denali Dually Duramax L5P
2015.5 Jayco Seismic 3902
2015 EZGO Express S4 buggy

DutchmenSport
Explorer
Explorer
To many folks here with PHD's in physics here. Simple solution .... just hook up the other hose and see if it works. I don't have a PHD in physics, just a bit of common sense. Actually, I'm not physical at all! I'm a vegetable, since I vegetate when I camp! Yup, no PHD for me!

Lowsuv
Explorer
Explorer
skipnchar wrote:
Water volume will be determined by the smallest diameter in the system between water source and the faucet.

Plumbers know three things :
Stuff flows downhill .
Payday is Friday .
A Steamfitter is a Plumber with a GED .

wa8yxm
Explorer III
Explorer III
I do not think it will make much difference, As the PEX in the RV is smaller. HOWEVER.. that said. The smaller the hose the more resistance to the flow of water... And that extra 1/8 inch will very likely make at least a small difference.

The biggest flow restriction in man RV's is the pressure regulator, they come in assorted types

Brass or plastic cylinder solid Very restrictive
Same with bright colored grip on female end (Camco has wings) still restricrive

Sur-flow (Often built into the city water inlet mine is an "in-line) slightly restrictive.

I just got a new ZURIN 70XL 3/4 inch with hose fittings.. I set it for 50 PSI, then turned on the outside shower and the pressure remained at 50 PSI

(With the sur-flo it dropped to about 10 Nt old Watts to 20, ,, NOTE the word "OLD" preceeding Watts. I think it is in need of a rebuild kit. but alas. I'm a couple parts short. If I ever fix or find the missing part I will get a rebuild kit and try it again.. it is old and much abused)
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times

mlts22
Explorer
Explorer
There is one time where diameter matters, and that is if using a macerator pump. There, an oversized hose will be very useful.

Hank_MI
Explorer
Explorer
An RV just doesn't have enough plumbing to make a difference. Most of my house which is considerable larger is only 1/2" copper.

nomad297 wrote:
skipnchar wrote:
Water volume will be determined by the smallest diameter in the system between water source and the faucet.


This.

Bruce


Not really true. It's not a case of "The weakest link". The longer the restriction, reduced diameter, the lower the flow. Each restriction you add even if they're all the same diameter will reduce the flow.

nomad297
Explorer
Explorer
JBinOR wrote:
nomad297 wrote:
skipnchar wrote:
Water volume will be determined by the smallest diameter in the system between water source and the faucet.


This.

Bruce


Not necessarily when you factor in the fact that we are also reducing the pressure. Flow is directly related to pressure and the area of the cross section. If we decreased the pressure while keeping the diameter the same, we would decrease the flow, but by increasing the diameter, we may be able to recoup some of that loss.


Who are "we," and what does pressure have to do with this?

I suppose we could just stick some 1/2" stand pipes up through the ground along the streets and as long as the fireman puts a 2" hose with a 2"x3/4"HT adapter on it, he will be able to get the same volume of water as he would from a normal fire hydrant.

Once the restriction is there, you cannot increase the volume. When the restriction is at the source, how are you going to increase the pressure to give you more volume?

Just wondering.

Bruce
2010 Skyline Nomad 297 Bunk House, 33-1/4 feet long
2015 Silverado 3500HD LTZ 4x4, 6.0 liter long bed with 4.10 rear, 3885# payload
Reese Straight-Line 1200# WD with built-in sway control
DirecTV -- SWM Slimline dish on tripod, DVR and two H25 receivers

Old-Biscuit
Explorer III
Explorer III
You can hook you a 2" hose........plumbing inside RV is 1/2"
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

JBinOR
Explorer
Explorer
nomad297 wrote:
skipnchar wrote:
Water volume will be determined by the smallest diameter in the system between water source and the faucet.


This.

Bruce


Not necessarily when you factor in the fact that we are also reducing the pressure. Flow is directly related to pressure and the area of the cross section. If we decreased the pressure while keeping the diameter the same, we would decrease the flow, but by increasing the diameter, we may be able to recoup some of that loss.
1999 Chevy Express 3500 5.7L
Jayco 26BH

nomad297
Explorer
Explorer
skipnchar wrote:
Water volume will be determined by the smallest diameter in the system between water source and the faucet.


This.

Bruce
2010 Skyline Nomad 297 Bunk House, 33-1/4 feet long
2015 Silverado 3500HD LTZ 4x4, 6.0 liter long bed with 4.10 rear, 3885# payload
Reese Straight-Line 1200# WD with built-in sway control
DirecTV -- SWM Slimline dish on tripod, DVR and two H25 receivers

skipnchar
Explorer
Explorer
Water volume will be determined by the smallest diameter in the system between water source and the faucet.
2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
2004 F-150 HD (Traded after 80,000 towing miles)
2007 Rockwood 8314SS 34' travel trailer

US Govt survey shows three out of four people make up 75% of the total population

nomad297
Explorer
Explorer
down home wrote:
I have had a one inch water hose. It delivers more flow if your water pressure and flow is high enough.


Again, the size of the hose won't make a difference if you are hooking up to a standard hosebib/sillcock or boiler drain. Even the 3/4" versions of these valves are restricted to less than 1/2" at the seat. There's nothing you can do about that -- once it is choked down, that's all you're going to get. Now, if you are coming straight off of a 1" pump or other source with a 1" hose with no restrictions from one end to the other, that's a different thing.

Bruce
2010 Skyline Nomad 297 Bunk House, 33-1/4 feet long
2015 Silverado 3500HD LTZ 4x4, 6.0 liter long bed with 4.10 rear, 3885# payload
Reese Straight-Line 1200# WD with built-in sway control
DirecTV -- SWM Slimline dish on tripod, DVR and two H25 receivers