[SPE]

http://www.machinemart.co.uk/shop/product/details/051012200?da=1&TC=RV-051012200

for my hf5 4040 ro as mentioned in previous post
have been into my local machine mart to check in stock, on a budget so cant spend more than this , my supply is 30 psi, states a max of 60 lpm but staff were unsure as to what psi it would boost my supply to as it doesnt state this in the spec ?
worth a punt or not ?
Simon

[AS Window Cleaning]

June at gaps water is a fountain of knowledge. I'd worry by getting a pump not up RO job you will wear membrane quicker. this one looks ok tho.... there's a certain type u need....can't remember the term for it.....

[alanwilson]

to calculate max pressure divide max head by 10

so for the pump mentioned - max head 46mtrs/10 = 4.6barx 14.7 = 67.6psi

so the pump is rated to work at pressures up to 67psi.

[AS Window Cleaning]

centrifugal! that's it

[SPE]

centrifugal! that's it

thankyou alan ,

Gaps recommend this pump though ( max lpm 101 )
http://www.machinemart.co.uk/shop/product/details/cbm240-1in-multi-stage-water-pump

at twice the price and with those maths the max pressure would be 70.56 !, not much of a gain for the money.

[AS Window Cleaning]

that's the pump I use. it's excellent. it's not just pressure tho, I think it's how it handles, or pulsates with the water too.

and I preferred to go with what the people in the know suggested. go for the cheaper one, you can let us know how well your membrane lasts!

[SPE]

that's the pump I use. it's excellent. it's not just pressure tho, I think it's how it handles, or pulsates with the water too.

and I preferred to go with what the people in the know suggested. go for the cheaper one, you can let us know how well your membrane lasts!

Its more a question of finances than going against what those in the know suggest, if I could make do in the meantime I may well be able to buy the CBM40 in a couple of months.
Do you know what its boosting your pressure to ?  is it 70 psi as Alans maths are suggesting or more ?
thanks
Simon

[AS Window Cleaning]

my pressure was being boosted from 40 at the filters (at 50% waste) to 90 at one house, and when i moved over 100psi.  Depends on how good the flow rate is too, as well as the pressure feeding you.

I know, but its false economy spending less on something if it kills your several hundred pound membrane in the process sooner.  But i dont know if it will or not, only one way of telling if nobody knows!

 bought mine for £240.....and still going strong after 2 years (tho not using it as booster anymore, its my transfer pump!)

[SPE]

ok thanks very much for the advice, my thoughts are any booster pump is going to be better than none for my membrane. For the next week atleast I'm going to think it over, try to shorten the feed from the supply and fit an inline tds and change my resin.
thankyou for the help
Simon

[AS Window Cleaning]

no worries, u can update this thread if any improvements!

[SPE]

I am one step closer to sorting it now!
cant believe I've overlooked this for so long.
Yes the pressure guage did read 30 psi after the prefilters situated 2 meters from the mains tap
just re arranged everything and put prefilters and guage 1.5 meters before ro (1st floor landing) thats now about 5 meters + from the tap, yep you've guessed it = reduction in pressure, realistically its been supplying water at more like 15 psi to the ro.
This isnt a new set up either, I've had this nearly 4 years STUPID ME  :!

Being in a top floor flat of a coverted house with the gf hallway being a communal one, I have no option but to run as much hose as I do from tap to ro (not without plumbing work anyhow which not really an option and want to move asap)

Booster pump now top of my list 
Simon

[alanwilson]

SPE - thats what the pump is rated for, as in, a safe working pressure.  They will provide more witha reduced flow rate and obviously putting more pressure on the pump.

Whether it will handle operating at higher pressures for any length of time is anyones guess.

[DaveG]

We've got that pump and it boosted our pressure from 30 to 75 psi. Great pump in my opinion . 

[SPE]

We've got that pump and it boosted our pressure from 30 to 75 psi. Great pump in my opinion . 

great thats good news thankyou