hooking mutilple 4040 reverse osmosis together

hi can anyone shed light on this situation of hooking 2 or more 4040 ro up together ive read a few threads on here but stilll no wiser

1 looking to see what way its hooked up

2 need more pure water faster

3 wen it comes outta 2 how much waste is returned

any help would be great

You can either link them in parallel or in series.

In parallel means that you split the water pipe from your prefilters into 2 and fit them to the inlets of both 4040 housings. Join the two waste outlets together and then put a gate valve on the single pipe after the join so you can throttle back the waste on both membranes. Obviously join the pure outlets together and run the single pure line to your di vessel or holding tank. (I prefer a gate valve as I drill a small 1 mm hole through the brass 'shutter' to ensure that I can never completely shut the valve by mistake and damage the membranes.)

The most common way to join housings together is to put them in series.

The main hose from your prefilters goes to the inlet of the first housing. You then pipe the waste from the first housing to the inlet of the second housing. The waste of the second housing has a gate valve (or ball valve) so you can throttle the waste back. The pure outlets from both housings need to be joined together and then the single pipe either goes to the di or to the holding tank.

I would prefer the first method as both membranes get an equal tds input. If you join them in series the second membrane works harder as it has to deal with a higher tds input than the first membrane has to. (Our tap tds is quite low at 120ppm. The waste water after the membrane is around 160ppm if my memory serves me.)

You need plenty of water pressure and flow to run 2 x 4040 membranes.

I can't answer your 3 question. Our waste goes off to the drain. There is some system - I think Ionics has it (Roback?) which does allow some of the waste water to be reintroduced into the feed line, but I don't know how it works. What it does mean that the r/o membranes will take even more of a hammering, but I guess its all about balancing membrane replacement costs with water costs.

Lee Pryors has/or had this as part of his filtration unit.

http://pryors-uk.com/

hi spruce, you seem to be the pro on this, 

i've tried tee'ing off twin membranes but not sure this booster pump can increase psi on 2 membranes. not seen an increase in production so far, works ok with one membrane.  https://www.thecleaningwarehouse.co.uk/water-genie-4040-booster-pump-5688-p.asp

can you recommend a company that know what they are doing with twin 4040's and booster pumps.

dave83 said:

hi spruce, you seem to be the pro on this, 

i've tried tee'ing off twin membranes but not sure this booster pump can increase psi on 2 membranes. not seen an increase in production so far, works ok with one membrane.  https://www.thecleaningwarehouse.co.uk/water-genie-4040-booster-pump-5688-p.asp

can you recommend a company that know what they are doing with twin 4040's and booster pumps.

Click to expand...

This is a question you will need to ask The Cleaning Warehouse. They will have the output specs graph of pressure verses flow for that pump. But as you already have one and it isn't working then the pump isn't delivering the needed volume of water at the required pressure.

Take a look at Grippa's selection of booster pumps.

https://www.grippatank.co.uk/wfp-purification-systems/water-treatment/booster-pumps

You will see pumps ranging from 600lph to 3100lph. (The 600lph pump is big enough to supply 1 4040 membrane but not 2.)

The other problem you could well have is the amount of water you need to run 2 x 4040 membranes. The figure Gardiners advised once was 9lpm for a single 4040 unit. So 2 units would need twice the amount of water.

According to the water regulations in the UK, you aren't allowed to draw more that 12lpm of water from the water mains directly if you have a booster pump. (It could well be that in certain areas the flow of water from the tap exceeds 12lpm. Ours, for example, is 13lpm with 50psi wp.)  2 x 4040 membranes will be drawing more than the regulatory 12lpm, so to have 2 x 4040 r/o membranes working together you will need to fit a large break tank. In many cases this would probably be impracticable.

Often the reason for needing a faster r/o is because of the number of operatives drawing water from a single supply, ie cleaners with multiple vans. So my suggestion would be to add another couple of IBC tanks and incorporate an automatic controller system that will shut off water production when all the tanks are full. That way you will have to option of replenishing your available water overnight.

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You really need the specification of the pump to determine if it is the correct pump to do the job. The pump might say 11 litres per minute but it is important to know what the closed flow rate is at xxx psi.

For example if it only does 6 litres at 100 psi then you would get around 2.5 litres of pure so with this pump would be more beneficial to link the waste to the second membrane as the pump would not be powerful to feed two membranes.

The Cleaning Warehouse description is not that very clear. 

I've got a lot of notes back at the office so will try and reply back next week.

We draw more than 12lpm.

Using WO  and FH we can sometimes hit 80 Lpm. You need to do a quick test and get your certificate though. I’ve thought about running two or three 4040s at the same time. Be great to hear what results others have had.

thankyou doug and spruce good info, i've got decent flow off the tap. 25 litres in 34 seconds. tap is seperate from the building so it cannons out.

looking at grippatanks pumps as machine mart tecnical department couldn't guarantee they could do the job.

grippatanks are quite abit of money but i guess you get what you pay for