Hose Length and H20 Pressure Drop?

[fireandrain 39]

Thanks for all of your replies to my previous posts, you have all been a HUGE asset to my goal of graduating from the school of hacks into a more informed and meticulous professional... Thanks!

Heres the latest installment in my general pw questions...

Im running a cold 3600PSI, 4GPM unit. I sometimes QC (2) 50ft. hoses to get further into my job without having to wheel the pw around. I dont seem to be losing much (if in any) pressure when I connect the 2 lengths. Ive read on a post somewhere that some guys run up too 200ft. of hose!

Can I do the same thing, say QC (4) 50ft hoses w/ my machine WITHOUT a big drop in my PSI? I know, another elementary question from yours truly, but I just wanted to make sure before I bought anymore hose and QC's.

Much Appreciated!

Matt

[CCPC 26]

Most definitely. A lot of guys run upwards of 300 -400 ft., you'll lose a little buy no too much. I personally don't like to use more than about 250ft of hose when all possible. Also becasuse I think I would loss some chem pull ability with more hose than that. The only place you will really notice the change in flow/pressure with an extra 100' of hose is when using a surface cleaner.

[John Doherty 126]

Matt,

You will lose a small, barely noticable amount of pressure, there's a formula for it out there somewhere. I would be more concerned with that many lenghts of hose and all those qcs, I'd at least get 100' lengths. My pw work required exactly 150' of hose, I would order that length, then I'd only have to worry about 2 qcs and 2 o-rings.

All of my hose failures have been at the hose ends, w/4 50' lengths that's 8 ends, 2 100' lengths is only 4.

John

[Don Phelps 85]

Approximately 90-100 psi per every 100'.

[Adrian 155]

It's around 30 psi per 50ft that you lose & and you are pushing enough psi and gpm that there will be barely any noticable drop in the PW 's ability to complete your job. It is normal to run 200 ft of pressure hose. Plus your speed will increase as you will no longer need to shag the PW unit around, not to mention the wear and tear on the spine and arms. You will appreciate the favor you are doing yourself by increasing hose length. Leave the unit on the trailer and unroll the hose. Working at a faster pace will increase the DPH as well.

What is DPH you ask. I just made it up as I was replying (dollars per hour).

[Ron Musgraves 240]

all my units have 300feet.....all calibrated to run full pressure at 300 feet.

That a close guess, about 100psi for 100 feet.

[fireandrain 39]

Man, thanks guys for the hose info! GREAT!:lgsideway Looking forward to dialing in the longer hose set up next week! I agree about going with the (2) 100's rather than (4) 50's... I already have 3 50's all QC'd so ill work with that first then upgrade soon. Figure you got to use what you got to get what you need!

Much Thanks!!!!!!!!!!!!!!!!

Matt

[Jeff 232]

I always have used 150 -200 ft with my 4gpm machines never take them off the trailer or before trailer never took them out of pick up. You'll like not having to take machine off, saves a ton of time. Ive used up to 300ft attimes. Not a big pressure lose for house washing.

[Jim Carroll 14]

all my units have 300feet.....all calibrated to run full pressure at 300 feet.

That a close guess, about 100psi for 100 feet.

I DO THE SAME AS RON, AND RUN 300-400 FEET. YOU LOSE TIME IF YOU HAVE TO MOVE YOUR RIG OFTEN.

[Apple Roof Cleaning 202]

all my units have 300feet.....all calibrated to run full pressure at 300 feet.

That a close guess, about 100psi for 100 feet.

That's pretty right on Ron!

And that is reason number one you NEVER want 3/8 hose in long runs on a Shurflo chemical pump.

With a decent pressure washing pump, you have PSI to spare, and might never notice the pressure drop, except on a surface cleaner, like Lance said.

But, it's death on a little Shurflo that only has 45 to 100 psi to offer.

The long 3/8 hoses pressure drop is so bad that it requires one to further restrict what little flow you have left with a small nozzle, to increase velocity so it can "spray".

BTW, though I am but a roof cleaner only, I do know some real successful commercial power washers here in my area, and they use bigger diameter hose then 3/8.

They swear by the bigger hose for cleaning parking lots, and large area's.

I posted a flow loss calculator in a roof cleaning thread about 3/8 hose.

Because I am not a Pressure Cleaner, I never explored the calculations for flow loss at higher pressures.

It might be interesting to see not how much pressure you pressure washing guys are losing, but how much FLOW as well, in a small 3/8 hose ?

I was told that GPM times pressure equals cleaning effectiveness, but again, that is just what I was taught over at Delco, and I am NOT a pressure washing expert.

I was also taught that the more GPM the better.

So, I can see why some of my commercial P/W friends use this larger hose.

For an equal amount of pressure and flow, a larger hose would appear to be always better, except dragging it around, LOL

I just may go do some calculations, because I am curious about this ?

It may be that because there is so much pressure to throwaway, that larger hose really don't matter ?

[One Tough Pressure 580]

According to the chart in the Dultmeier book, using 100 feet of 3/8" hose,

3 gpm = 50 psi

4 gpm = 90 psi

5 gpm = 130 psi

6 gpm = 220 psi

8 gpm = 300 psi

Using 100 feet of 1/2"

3 gpm = 13 psi

4 gpm = 24 psi

5 gpm = 34 psi

6 gpm = 52 psi

8 gpm = 80 psi

I use 1/2" hose for the first 100 feet off the reel. As I replace hoses, they will all be 1/2".

[Apple Roof Cleaning 202]

According to the chart in the Dultmeier book, using 100 feet of 3/8" hose,

3 gpm = 50 psi

4 gpm = 90 psi

5 gpm = 130 psi

6 gpm = 220 psi

8 gpm = 300 psi

Using 100 feet of 1/2"

3 gpm = 13 psi

4 gpm = 24 psi

5 gpm = 34 psi

6 gpm = 52 psi

8 gpm = 80 psi

I use 1/2" hose for the first 100 feet off the reel. As I replace hoses, they will all be 1/2".

I hear you man!

Here is another link I found http://www.ultimatewasher.com/hose-pressure-loss.htm

It agrees closely with your findings.

One will notice that at larger Gpm, pressure drop increases drastically.

Gosh, no wonder all my friends who are doing commercial P/W with high GPM pumps use the big stuff!

I can tell you this, my commercial roof cleaning truck uses 5/8 hose, and my everyday ones uses 1/2 inch, same pumps.

The commercial truck will simply walk away from the residential when it comes to speed.

Hose length is 250 to 300 feet on both, give or take.

I think I saw Don or Lance, or somebody, give an excellent recommendation to a newbie, suggesting he unroll all his hose when max pressure was required.

These calculations do not include some real world losses like coiled hose, or height above ground.

There are some other advantages to big hose too, LOL

My friend Joe, from Signal Commercial in S.W. Florida was up here in Tampa, and we were out Bar hopping.

We spotted a cute lady outside, and went to go talk with her.

A "pseudo biker" asked her if she wanted to go for a Harley Ride, and she was gone, just like that.

Joe looked at me and said "Dam Chris, I wish I had my rig up here"

Puzzled, I asked him how his beautiful commercial rig, as pretty as it is, could possible compete with a nice Harley Davidson ??

He just smiled confidently, and said he would simply ask her to come to his trailer, and see his "Big Hose"