New brush and first time with 3mm jets

[Stevie G]

I've recently bought a ultimate hybrid brush 26 with 2x 3mm jets.im using a 6mm hose from a pure freedom trolly which is attached to a tank system in the van. I fancied giving the 3mm jets a go and see what the benefits or downsides were compared to 2mm were. I usually have my flow set at 40 in the winter,so set it at 80 for the 3mm. All was ok for a day,then second day the flow began stop starting every few seconds with de coming up. I checked all hoses and connections ect but nothing visalby wrong,so I phoned pure freedom and he suggested that the 6mm hose wasn't coping with the hi flow. So I turned it down to 50 and no more problems. Only time will tell if this is going to work of course.I've been cleaning wfp for 6yrs(20 +trad)and always rinsed off the glass. I've been rinsing on the glass with new brush and big jets and I love it but I've only had full overcast days and no bright sunshine which would show up any problems from this new technique straight away. I've hung around on the first few houses in the same street to see if they dried ok and all seems well. But it will take me to do a full round and different conditions to see how well it works. 

Does anybody else use 3mm jets and is 50 to low in your opinion? Is it to low to be rinsing on the glass? 

Ps majority of my work is right on the coast!!

 

[Pjj]

We do a lot of costal work and use 6 mm microbore with 2 mm jets , I did use 3 mm years ago when I first started and liked the flow ,but someone I think it might have been Alex Gardiner suggested trying 2 mm and I stayed using them ,it does  use a lot less water , when doing costal stuff that’s very bad I do up  the flow rate on the controller sometimes to maximum just for those bad jobs ,and we don’t get any problems working this way , it’s a matter of personal preference there is no right or wrong .

 

[Stevie G]

We do a lot of costal work and use 6 mm microbore with 2 mm jets , I did use 3 mm years ago when I first started and liked the flow ,but someone I think it might have been Alex Gardiner suggested trying 2 mm and I stayed using them ,it does  use a lot less water , when doing costal stuff that’s very bad I do up  the flow rate on the controller sometimes to maximum just for those bad jobs ,and we don’t get any problems working this way , it’s a matter of personal preference there is no right or wrong .

Thanks pjj I may well go back to 2mm in the future. That's all I know at the moment so just having an experiment. 35 cm 4x1.4 is another option that I fancy trying sometime. But I will wear this brush down first but may change the jets back. 

 

[scottish cleaning service]

3mm jets are okay for a first clean but the optimum on here is 2mm and even 1.4mm for a wide brush with 4 jets I have noticed. ?

 

[Stevie G]

3mm jets are okay for a first clean but the optimum on here is 2mm and even 1.4mm for a wide brush with 4 jets I have noticed. ?

That's useful thanks mate 

 

[spruce]

I've recently bought a ultimate hybrid brush 26 with 2x 3mm jets.im using a 6mm hose from a pure freedom trolly which is attached to a tank system in the van. I fancied giving the 3mm jets a go and see what the benefits or downsides were compared to 2mm were. I usually have my flow set at 40 in the winter,so set it at 80 for the 3mm. All was ok for a day,then second day the flow began stop starting every few seconds with de coming up. I checked all hoses and connections ect but nothing visalby wrong,so I phoned pure freedom and he suggested that the 6mm hose wasn't coping with the hi flow. So I turned it down to 50 and no more problems. Only time will tell if this is going to work of course.I've been cleaning wfp for 6yrs(20 +trad)and always rinsed off the glass. I've been rinsing on the glass with new brush and big jets and I love it but I've only had full overcast days and no bright sunshine which would show up any problems from this new technique straight away. I've hung around on the first few houses in the same street to see if they dried ok and all seems well. But it will take me to do a full round and different conditions to see how well it works. 

Does anybody else use 3mm jets and is 50 to low in your opinion? Is it to low to be rinsing on the glass? 

Ps majority of my work is right on the coast!!

You might be able to increase your flow a little by recalibrating your controller.

Try to read through this recent topic. Although @TWC problem is not exactly the same as yours, what @Ian Sheppard writes regarding this also applies to your situation.

https://windowcleaningforums.co.uk/topic/31673-flow-problem-when-rinsing/?tab=comments#comment-443147

Sometimes increasing the flow rate on the controller does very little at the brush end due to what you have already noted.

Point to remember;

1.4mm jets are about half the size of 2mm jets. 2mm jets are about half the size of 3mm jets.

About 3 years ago I posted this on another forum. It was a poster remarking how there was a difference in flow using 6mm hose from when he was using 8mm hose.

Another poster on this forum couldn't understand why a difference in 2mm hose size (8mm minibore to 6mm microbore) should make a difference in flow. Doug Atkinson from Daqua posted this in reply

It does -------, makes at least 30% reduction in flow
 

Take a look at this;

http://www.flourmilling.co.uk/water.html (Sadly this link doesn't work any longer)

I realise its steel pipe but I see the flow rate difference between 6mm and 8mm bore steel pipe is considerable. At 4 bar the flow through 6mm pipe is 0.022 liters per second. The 8mm pipe its  0.056 liters per sec at the same pressure. So a 6mm tube will only allow fractionally less than 1/2 the volume of water at 4 bar. Our hose coiled up around a hose reel will probably reduce those figures a bit more.

Hot water will have a higher (or is it lower) viscosity (less dense) so will flow better through a smaller diamt hose. So most hot water users happily use microbore hose.


http://www.frca.co.uk/Documents/100308 Physics of flowLR.pdf

Interesting read these 7 pages.

Look at the difference between Laminar flow and Turbulent flow. Once fluid in a tube reaches a certain speed it become turbulent. Once it becomes turbulent it requires 4 times the amount of pressure to double the flow rate. Fluid through hose coiled on hose reels won't be laminar in flow but turbulent.

To calculate the area of a circle the formula is

A = π r2

A 6mm id hose is fractionally more than half the size of an 8mm hose.
A 3mm jet is a little more than twice the size of a 2mm jet.
A 1mm jet is about 1/4 of the size of a 2mm jet.

@ian Sheppard responded

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

 

[Stevie G]

You might be able to increase your flow a little by recalibrating your controller.

Try to read through this recent topic. Although @TWC problem is not exactly the same as yours, what @Ian Sheppard writes regarding this also applies to your situation.

https://windowcleaningforums.co.uk/topic/31673-flow-problem-when-rinsing/?tab=comments#comment-443147

Sometimes increasing the flow rate on the controller does very little at the brush end due to what you have already noted.

Point to remember;

1.4mm jets are about half the size of 2mm jets. 2mm jets are about half the size of 3mm jets.

About 3 years ago I posted this on another forum. It was a poster remarking how there was a difference in flow using 6mm hose from when he was using 8mm hose.

Another poster on this forum couldn't understand why a difference in 2mm hose size (8mm minibore to 6mm microbore) should make a difference in flow. Doug Atkinson from Daqua posted this in reply

It does -------, makes at least 30% reduction in flow
 

Take a look at this;

http://www.flourmilling.co.uk/water.html (Sadly this link doesn't work any longer)

I realise its steel pipe but I see the flow rate difference between 6mm and 8mm bore steel pipe is considerable. At 4 bar the flow through 6mm pipe is 0.022 liters per second. The 8mm pipe its  0.056 liters per sec at the same pressure. So a 6mm tube will only allow fractionally less than 1/2 the volume of water at 4 bar. Our hose coiled up around a hose reel will probably reduce those figures a bit more.

Hot water will have a higher (or is it lower) viscosity (less dense) so will flow better through a smaller diamt hose. So most hot water users happily use microbore hose.


http://www.frca.co.uk/Documents/100308 Physics of flowLR.pdf

Interesting read these 7 pages.

Look at the difference between Laminar flow and Turbulent flow. Once fluid in a tube reaches a certain speed it become turbulent. Once it becomes turbulent it requires 4 times the amount of pressure to double the flow rate. Fluid through hose coiled on hose reels won't be laminar in flow but turbulent.

To calculate the area of a circle the formula is

A = π r2

A 6mm id hose is fractionally more than half the size of an 8mm hose.
A 3mm jet is a little more than twice the size of a 2mm jet.
A 1mm jet is about 1/4 of the size of a 2mm jet.

@ian Sheppard responded

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

Thanks very much spruce! When I was problem solving with man from pure freedom we did go into the calibration and he said it seems fine when I told him the reading. But what I need to do now is go back and do some more tests with the higher flow and try the recal again and see if that helps the flow. That's interesting stuff you've put up thanks m8

 

[spruce]

Thanks very much spruce! When I was problem solving with man from pure freedom we did go into the calibration and he said it seems fine when I told him the reading. But what I need to do now is go back and do some more tests with the higher flow and try the recal again and see if that helps the flow. That's interesting stuff you've put up thanks m8

Run your system with the higher flow with everything connected up with water flowing and then do an automatic recalibration. This will help the controller calibrate closer to your flow rate.

 

[Stevie G]

Run your system with the higher flow with everything connected up with water flowing and then do an automatic recalibration. This will help the controller calibrate closer to your flow rate.

Thanks spruce

 

[Ian Sheppard]

Thanks spruce

Hi Stevie

I agree with Spruce and as the flow rate is increased you will need to increase the calibration. What is a happing is with the flow set to 80, the cal value is to low and the controller will cycle the pump in/out of DE. You can run auto calibration at any flow rate. Stepp1 then will be to set the flow rate to the maximum your likely to use then run auto cal