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Is my pump good enough

Most people use 60 or 100 psi pumps but on a short length of hose or low heights it will work just not a great flow 

 
I did once read that you need 5PSI for each 10 feet your working at there is also a need to consider hose resistance. A 60PSI will [probably be the least you would want on a trolley. Interns of flow volume depending on what the site requires your probably looking fo flow between 1 to 2 lpm and a little more for rinsing.

This blog post does give a little more detail http://springltd.co/blog/84/flow-resistance-and-volume

 
The way most pumps are rated (I stand to be corrected here) is in two ways. Open flow rate and shut of pressure.

Though the two are connected they are not the same thing. 

The Flow rating stated on most pumps is in 'litres per minute' (lpm) with no output hose conected to the pump. The hose will provide resistence to this depending on it's bore and length. Hence the 'bucket test' to determine what it is nearer to in use. (This needs to be done with hose connected). However, this will only give you an approximate measure as when you raise the pole to working height this will get lower due to the pump having to lift the water to working height

Pressure is measured in Bar or PSI and refers to the back pressure at which the pump will 'dead end' or shut off when you shut off the flow with a valve of some sort.

In practice, if your pump is running smoothly and you can get enough flow at the brush without it shutting on and off whilst you are allowing your water to run freely then your pump is fine for what you are using it for. 

The pump I use is rated at 5Lpm but flat out gives me 2.5Lpm with 25mtrs of 5.5mm bore hose attached. The Pressure rating is 70 psi and is more than capable of lifting enough water to clean 3 storey town houses with ease.

 
I did once read that you need 5PSI for each 10 feet your working at there is also a need to consider hose resistance. A 60PSI will [probably be the least you would want on a trolley. Interns of flow volume depending on what the site requires your probably looking fo flow between 1 to 2 lpm and a little more for rinsing.

This blog post does give a little more detail http://springltd.co/blog/84/flow-resistance-and-volume
Thanks mate I will look into getting a higher psi pump 

 
If I were looking to replace my pump at the moment, this would be the pump I would be looking to try. Nice and lightweight, just right for a trolley with a 10 or 12ah battery and good for a solid days work.

https://www.ebay.co.uk/itm/12V-5L-High-Pressure-Diaphragm-Water-Pump-For-RV-Caravan-Boat-Garden-100PSI/163712157833

When I bought my last one it was a 5lpm 115psi pump and it was too strong for my univalve. When the pump dead ended there was so much pressure in the hose that the univalve became impossible to operate. They work best up to 100psi. So I fitted one of these which is adjustable and can be reused on any of these styled pumps

https://www.ebay.co.uk/itm/12V-70-PSI-PRESSURE-SWITCH-FOR-WATER-DIAPHRAGM-PUMP-Caravan-Boat-RV-Deckwash/361942361613

Of course, if you are using a digital controller with the calibration feature you shouldn't have to worry about this. Just set the calibration to switch the pump off before it gets anywhere near this pressure.

 
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