Am I the only one that runs my controller at 80?

[Part Timer]

No. If it were true there would be no such thing as a bottle neck surely.

But I have the feeling that this is getting into the territory of Bernoulli's principle which states: Within a horizontal flow of fluid, points of higher fluid speed will have less pressure than points of slower fluid speed. (I had to look this up. ? School days were a very long time ago.)

The next question is about what the difference of pressure (force) acting on the water flow in the hose is compared to the pressure of the same water leaving the jets of the brush.

What about the fact I have one pole hose but 4 pencil jets coming from it. I could understand if I only had one jet but wouldn't 4 equal this out. Please be gentle with me  :delusional:

 

[Pjj]

You've misread my post i think. My fav combo is a extreme brush with a rinse bar and then 2 1.4mm jets. You're looking at around 17 tiny jets coming out. So it's not like a pressure washer it's a really good flow. 

Ah yes , I thought you meant just the 1:4 mm jets 

What about the fact I have one pole hose but 4 pencil jets coming from it. I could understand if I only had one jet but wouldn't 4 equal this out. Please be gentle with me  :delusional:

@spruce is the man to explain this far better than me ???

 

[Damo]

Ah yes , I thought you meant just the 1:4 mm jets 

Nah you'd take the neighbours eyes out with them ? I tried both low and normal rinse bars but I just wasnt happy with the flow/volume.

Because the brushes are the new jet system i messed around for ages and finally found a combo i liked.

 

[Stevieboy]

There are a lot of people on here who could turn there flow down by 50% and still get the same results. Just need to wash the windows not flood them and definitely not ‘use the pressure to blast poo off’. 

 

[spruce]

What about the fact I have one pole hose but 4 pencil jets coming from it. I could understand if I only had one jet but wouldn't 4 equal this out. Please be gentle with me  :delusional:

Here's some bed time reading ?

This time I've got nought to do with it.

https://springltd.co/blog/84/flow-resistance-and-volume

 

[Marko067]

I use two 100° fan jets in a 26cm Tapertec Xtreme brush. I use an old style analogue PWM controller from Pure Freedom (now 13 yrs old). I dial it up till the pressure switch starts to kick in (chatter), then dial it back just a bit till the pump runs smoothly. This produces about 2 lpm through the brush from a 70psi pump. It equates to 90% (9/10) on the dial of my controller. 

 

[spruce]

I use two 100° fan jets in a 26cm Tapertec Xtreme brush. I use an old style analogue PWM controller from Pure Freedom (now 13 yrs old). I dial it up till the pressure switch starts to kick in (chatter), then dial it back just a bit till the pump runs smoothly. This produces about 2 lpm through the brush from a 70psi pump. It equates to 90% (9/10) on the dial of my controller. 

What flow rate is the pump? I can't remember what pump you have in your trolley.

 

[spruce]

I see people saying I run my controller at 25 or 35 and I'm like mines at 80!!!

I don't have an excessive flow but it's not weak as **** either, don't use loads of water so I guess I'm asking why? 

I've calibrated it with my biggest pole fully extended slx35 and fully closed but still only get the same flow rate when calibrated, am I missing something? 

A couple of months ago @Ian Sheppard had this to say in response to another poster who had a different question regarding hose size and length. His response also applies to your post regarding flow and pressure:

Switching to a smaller ID can and often will have an impact on flow. In reducing the ID of the hose by 25% the space available for water to flow is also reduced. The hose wall itself will have a maximum capacity to expand which will be less than the original 8mm hose. In effect the hose its self restricts how much water can flow through the line.

In running the controller at 99 the pump is trying to force the 4 - 5 LPM in to the hose. The fact the smaller ID hose restricts the flow increases the amount of back pressure in the system In effect the hose is working against the pump.

Part of the answer here is actually to turn the flow down so the back pressure is reduced, Increasing calibration may help because the harder the pump works the more current it draws ans the controller needs to know what this is.  My suggestion is to turn flow down to around 60 then go into the auto calibration menu of the controller. The need here is actually to reduce back pressure rather than increase it.

Calibration of the control allows the control to know the open flow current draw and base pressure of the pump. Smaller ID means the pump will have to draw more current to overcome the restriction in the hose. Hence Cal will likely need to be higher.
The combination of Cal that is to low plus high pressure may mean the pump is being cycled on/off this will also reduce flow.

The system can run well with 6mm ID hose but it has to be set up to suit. As the hose will create greater pressure flow rate can be reduced.

A 6mm id hose is fractionally more than half the size of an 8mm hose.  (A = π r2)

This will also add to @Part Timer's post regarding flow rates and pressure.

 

[Part Timer]

Here's some bed time reading ?

This time I've got nought to do with it.

https://springltd.co/blog/84/flow-resistance-and-volume

Will have a look when I finish work later today ?

 

[Dave B]

I use mine on 100 except on 1st cleans but recently have gone back to Gardiner 100° fan jets and use a swivel.

The brush never leaves the glass so bo splashback etc.

Very quick way of working.

Makes a lovely noise on the glass also.

 

[Marko067]

What flow rate is the pump? I can't remember what pump you have in your trolley.

Open flow is 5lpm. The pump is a backpack style pump purchased from eBay fitted with an adjustable pressure switch callibrated to 70psi

Before I switched to this pump I used the standard Sureflo 5.2lpm 100psi pump and used to do the same thing to tune the system. It too use to start chattering around the 90% (9/10) mark but using 2mm brass jets.

 

[spruce]

Open flow is 5lpm. The pump is a backpack style pump purchased from eBay fitted with an adjustable pressure switch callibrated to 70psi

Before I switched to this pump I used the standard Sureflo 5.2lpm 100psi pump and used to do the same thing to tune the system. It too use to start chattering around the 90% (9/10) mark but using 2mm brass jets.

View attachment 20351

Thanks. This is the exact point we were trying to make. Just because a pump is rated at 5lpm it doesn't mean it will deliver 5lpm of water with the controller on full wack.

If you turn your flow controller down by about 20% you will probably still get 2lpm of water through the jets.

 

[Wolfman]

I recently replaced old pump which I used to run at about 70, I couldn't believe people were running there's at 30 or 40.

New pump ran at 70 and ran out of water in no time and have had to turn down to 35 which puts out similar amount to old pump, so maybe like me you have an older inefficient pump that you have to turn right up

 

[Marko067]

If you turn your flow controller down by about 20% you will probably still get 2lpm of water through the jets.

This is likely true. It's one experiment I didn't try while measuring my setup with a bucket. I can see another measuring session in the offing.

However, I like the force at which the water hits the pane when rinsing in close at this setting. It often blasts any remaining little bits off the glass after scrubbing.

This is certainly an interesting topic as there are so many variables to consider when tuning your system and personal preference is one of them.

 

[Davy G]

I use mine on 100 except on 1st cleans but recently have gone back to Gardiner 100° fan jets and use a swivel.

The brush never leaves the glass so bo splashback etc.

Very quick way of working.

Makes a lovely noise on the glass also.

Ahh the sound of 100 degree fan jets on the glass. Another man embracing the fizz. ?

 

[dazmond]

I usually have mine on 40-45.....and its gushing out of the jets on that setting using hot water and 100m microbore...my water has been getting as hot as 60c during this warm weather...

 

[Ian Sheppard]

I see people saying I run my controller at 25 or 35 and I'm like mines at 80!!!

I don't have an excessive flow but it's not weak as **** either, don't use loads of water so I guess I'm asking why? 

I've calibrated it with my biggest pole fully extended slx35 and fully closed but still only get the same flow rate when calibrated, am I missing something? 

Each system will have its own little quirks and run slightly differently. These variances can be due to pump motor efficiency the amount of hose run off the reel. ID of hose. air temperature. Brush jets to name a few. There is also the personal factor in that each person will have a preferred flow rate that suits them and the work being carried out. In reality there is no ideal flow rate that suits all situations and people. because each will have their own preference that works for them.

 

[spruce]

I usually have mine on 40-45.....and its gushing out of the jets on that setting using hot water and 100m microbore...my water has been getting as hot as 60c during this warm weather...

Hot water flows easier than cold because it has a different viscosity.

 

[Part Timer]

No you are trying to force the water out of a smaller orafice so pressure will increase but volume will decrease 

Here you go @spruce, bored today so did a small test. Calibrated at 65, flow set at 45, through 100m 8mm hose and using 4 x 1.4mm pencil jets.

Using a short length, circa 8" minibore it took 58 seconds to fill a 2 litre bottle. Through the pencil jets it took 1 minute 3 seconds.

Let me know if that is correct using the formula you posted ?

 

[Pjj]

Here you go @spruce, bored today so did a small test. Calibrated at 65, flow set at 45, through 100m 8mm hose and using 4 x 1.4mm pencil jets.

Using a short length, circa 8" minibore it took 58 seconds to fill a 2 litre bottle. Through the pencil jets it took 1 minute 3 seconds.

Let me know if that is correct using the formula you posted ?

Lol you must be board ?? I cannot be bothered to go into the science but yes you are right , bare in mind most people  only use two jets as well so there would be an evan greater difference . 

 

[spruce]

Lol you must be board ?? I cannot be bothered to go into the science but yes you are right , bare in mind most people  only use two jets as well so there would be an evan greater difference . 

4 x 1.4mm are virtually the same as having 2 x 2mm jets. 1.4mm are fairly close to 1/2 the size of 2mm jets.

Using that straight steel pipe experiment 8mm ID pipe delivered 3.36lpm of water at 4 bar (58psi). What we don't know is what turbulence was in the pipe which would have reduced to flow from the magic 3.36lpm in straight pipe.

For me it doesn't matter as the 8mm we have always used delivered enough water for us to wash and rinse window comfortably. We used much less water going to minibore with added controllers and 2mm jets than earlier with the same setup using 1/2" hose, no controllers and 3mm jets.

Where I immediately noticed a difference was when I replaced the minibore on one hose reel with microbore on the same controller using the same settings. This was even more evident when the water was colder in winter.

For the guys using hot water the flow through microbore is fine. Using those same settings they will notice a difference when using cold.

@Part Timer. In summer the microbore still performs within our demands. Microbore in winter needs an extra calibration setting to achieve this.