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Andy Hill

Poor pressure - slow fill

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Andy Hill

New to the game. Just got myself a used van already kitted out with a pure freedom system. Got about an 8ft run from my outside tap to the fill valve on the back of the van. Pressure is not great. Been filling my 500l tank for 24 hours and stil only half full! Any recommendations for a not too pricey pump? Or other solutions to get this process down from days to hours!! 

TIA

Andy

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Tuffers
30 minutes ago, Andy Hill said:

New to the game. Just got myself a used van already kitted out with a pure freedom system. Got about an 8ft run from my outside tap to the fill valve on the back of the van. Pressure is not great. Been filling my 500l tank for 24 hours and stil only half full! Any recommendations for a not too pricey pump? Or other solutions to get this process down from days to hours!! 

TIA

Andy

 

So you have the RO on the van yeah? What is your tap water pressure? Have you got the gate valve open so that the system is on 'flush'?  Could you fit a booster pump to your setup?

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Part Timer

It sounds like you've either got very low water pressure or your flush valve is open. There should be a valve just beside your R/O, if the water coming out of the waste pipe is far greater than what's going into the tank then open the valve. If this doesn't alter the waste to pure ratio then it sounds like you need a booster pump. 

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Tuffers
2 hours ago, Part Timer said:

It sounds like you've either got very low water pressure or your flush valve is open. There should be a valve just beside your R/O, if the water coming out of the waste pipe is far greater than what's going into the tank then open the valve. If this doesn't alter the waste to pure ratio then it sounds like you need a booster pump. 

 

You mean close the valve PT? Add words so I can reply 🙄

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Part Timer
55 minutes ago, Tuffers said:

 

You mean close the valve PT? Add words so I can reply 🙄

Yes mate and I've had to as well 

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Andy Hill

Thanks guys, 

Yep RO, with valve fully closed. Getting a smidge over 3bar from my tap. Certainly more going to waste than in the tank! What pump would you suggest? And where exactly do I position it? Sorry to sound like a clueless beginner....but I'm a clueless beginner!! 

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ks789

No, dont have the valve fully closed, can ruin the ro. Experiment with it to get the best tds. Could be 2 go to waste for every 1 to pure or nearer 1 to 1 or could be worse and 3 waste to 1 pure. But yes, could need a booster pump. certainly can fill up a lot quicker. Best phone one of the companies ( got mine from daqua, they will tell you if its needed)

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Andy Hill

Cool. Ta. 

Will try pure freedom first. 

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Iron Giant

@Andy Hill I would upload pics of your system so we can see what you've got, as mentioned above flow rate of waste will always be higher but you will need to find the sweet spot along with the right pure output tds reading depending on your tap tds, do you have a tds meter to check your water quality both directly from your garden tap and pure output from your R/O

If you can provide both tds readings, lads on here with a similar tap tds will be able to let you know what performance and production you should expect from your R/O 

If the guy who sold you the van and system didn't talk you through the system then you also need to know how old the prefilters are what use they have had etc along with your R/O membrane(s) 

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Andy Hill

Thanks. 

TDS from my tap is 205. 

Pre DI it's 4.

Got a response from pure freedom this morning to clarify on position of the valve... 

"The red waste valve needs to be fully closed.

It has a pre-drilled hole in it for the waste.

This may sort out the slow filling problem for you".

 

The guy I bought it from was a bit like me in that he wasn't a time served windy. He only ever did it on a part time basis to supplement his income. So although he walked me through things I'm no expert. Everything worked but now, further down the line, I need to iron out these issues. As the TDS is reading 4 I've left the pre filters. But I have spares so will fit them to see if that improves anything. 

I've opened the valve for 20 minutes to flush the membrane this morning but no improvement.

I'm guessing it's either water pressure or the membrane needs replacing. 

Thank you for your guidance. 

Andy

DSC_0149.JPG

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Dave B

If the pre filters are knackered/clogged that will slow down water flow through the system

Go to screwfix and get a pressure gauge for 11 quid that screws on to your garden tap to see the water pressure

Anything under 50psi will probably need a booster pump unless you have a low pressure membrane

You need to find out what membrane you have ideally

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spruce

Its a 4021 r/o so it will produce water at about 1/2 of what the standard 4040 does. Expect around 1lpm of pure. Under idea conditions that tank will take 11 hours to completely fill.

 

I would invest in a water pressure gauge and test what your water pressure is at the van. The gauges are available from any plumbing outlet, Screwfix, Tool Station etc. Water pressure is important as is the amount (liters per minute) of water flowing through the pipe.

 

Now, I would ask you to measure the amount of pure your are producing against the amount of waste as we need to know what the pure to waste ratio is. If your water isn't too hard then its about 1 liter of waste to 1 liter of pure. At the most it will be 2 liters of waste to 1 liter of pure for hard water.  My gut is telling me that the waste gate valve is a problem. As has been said, PF drill a hole in the gate valve paddle to get the ratio right for a 4040.

 

I would buy a replacement gate valve and fit that. But its important that you don't close it fully.

 

The other thing to do is measure how many liters of water you get at the van unrestricted.
 

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doug atkinson

I would say probably the membrane has dried out due to not being used that lot. Sometimes flushing it for a good hour and resurrect it. If it doesn’t then new membrane required. We have very low pressure in our unit when testing systems and at 2 bar get a litre every 2 mins 10 secs

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Ana

I'm in the process of filling my 25 litre containers right now, been running for a few hours and have three tanks full already. Waste is being directed onto a large raised bed as I refuse to pay twice for water (I'm on a meter)

 

Wouldn't a booster pump be worth while if your getting slow flow @Andy Hill ? I'm still wondering about getting one for my 450 gpd but I'm unsure of my starting pressure (need a gauge to test really) and also what gpd booster pump I should buy.

 

regarding booster pumps could you not use a booster pump you use in a shower system with hoselock fittings? If so half the price of a pump typically used from vyair and the like?  

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spruce
35 minutes ago, doug atkinson said:

I would say probably the membrane has dried out due to not being used that lot. Sometimes flushing it for a good hour and resurrect it. If it doesn’t then new membrane required. We have very low pressure in our unit when testing systems and at 2 bar get a litre every 2 mins 10 secs

 

I would still do the numbers Doug to rule out if low water pressure and flow rate being the problem. I would check everything else before resorting to replacing the most expensive component.

At times our water is full of sediment and a blocked sediment filter will play havoc with production. We have clear housings on our prefilters so its easy to see at a glance what the situation is. We also have a pressure gauge on each side of the prefilters to monitor flow restrictions through the sediment filter.

I once also fitted a 1 micron carbon block. That blocked up very quickly even with a 5 micron sediment filter infront of it.

 

Interesting production figures at 2 bar. Our 4040 produces 2lpm at 50psi with a 50/50 ratio of waste to pure. If the o/p has similar water pressure at his prefilters then filling a 650 liter tank is going to take his a long time.

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spruce
28 minutes ago, Ana said:

I'm in the process of filling my 25 litre containers right now, been running for a few hours and have three tanks full already. Waste is being directed onto a large raised bed as I refuse to pay twice for water (I'm on a meter)

 

Wouldn't a booster pump be worth while if your getting slow flow @Andy Hill ? I'm still wondering about getting one for my 450 gpd but I'm unsure of my starting pressure (need a gauge to test really) and also what gpd booster pump I should buy.

 

regarding booster pumps could you not use a booster pump you use in a shower system with hoselock fittings? If so half the price of a pump typically used from vyair and the like?  

 

You need to correct me if I'm wrong but Salamander booster pumps are volume boosters rather than pressure boosters.

https://www.salamanderpumps.co.uk/pumps-explained-homeowner.php

According to the specs they rate their pumps at 1.5 bar, 2 bar and 3 bar. 3 bar is not a lot of water pressure. I looked into this many years ago and their booster pumps are designed to stay within the water authority rulings of 12lpm max draw through a supply pipe. It was all about supplying enough water for a user to get the benefit of a fitted power shower.

 

Your 450gpd r/o uses a piddly amount of water, so a large booster pump like we would use on a large r/o (eg 4040) isn't suitable for your application.

 

I'm pretty sure @doug atkinson responded to a small r/o booster pump query recently. I haven't looked on his site but Purefreedom sell a 24v Aquatec booster pump that they say is suitable for a 450gpd r/o

https://purefreedom.co.uk/product/24v-aquatec-reverse-osmosis-booster-pump/

 

 

Edited by spruce

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Andy Hill

Thanks for all the replies guys. Really appreciate it. Apologies if I appear slow in responding. I'm giving up 20 years as a manager to start up this but still got my day job...for now! 

Have now changed the pre filters but without much noticeable difference. Will try the suggestion of flushing for an hour. 

And will invest in a booster pump regardless. 

Water pressure is just on 50psi. 

Not sure about the position of the gate valve. Pure freedom state it should be fully shut whearas some advice is to not fully shut it. May replace it regardless to eliminate as a potential problem. 

Will try and make some progress with it over the next few days as and when I get time! And will let you know how I solve it. 

Again, really appreciate the advice and guidance. 

Andy

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doug atkinson
3 hours ago, spruce said:

 

You need to correct me if I'm wrong but Salamander booster pumps are volume boosters rather than pressure boosters.

https://www.salamanderpumps.co.uk/pumps-explained-homeowner.php

According to the specs they rate their pumps at 1.5 bar, 2 bar and 3 bar. 3 bar is not a lot of water pressure. I looked into this many years ago and their booster pumps are designed to stay within the water authority rulings of 12lpm max draw through a supply pipe. It was all about supplying enough water for a user to get the benefit of a fitted power shower.

 

Your 450gpd r/o uses a piddly amount of water, so a large booster pump like we would use on a large r/o (eg 4040) isn't suitable for your application.

 

I'm pretty sure @doug atkinson responded to a small r/o booster pump query recently. I haven't looked on his site but Purefreedom sell a 24v Aquatec booster pump that they say is suitable for a 450gpd r/o

https://purefreedom.co.uk/product/24v-aquatec-reverse-osmosis-booster-pump/

 

 

 

I'm scratching my head at Pure Freedom's review of that booster pump as does not add up. When you see what it performs it does not perform to the full expectation of the membranes as if you ticked all the boxes for a 300 GPD it would take 5 hours 30 mins to fill 250 litres.

 

The 8800 pump there are 3 series of pumps and depending what series they sell 2 of them would not be suitable for a 450 gpd.

 

Our 4021 booster pump will do 90/100 litres an hour but that is the closet booster pump I could find.

 

I've been trailing 500 GPD membrane with booster pump and well impressed with result at 78 litres an hour.

 

We also have a 4040 booster pump under trials which has been specked out for us and the aim is 400 litres an hour.

 

Next on plan is a system doing 800 litres an hour.

 

Problem is time getting these up and running

Edited by doug atkinson

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spruce
42 minutes ago, Andy Hill said:

Thanks for all the replies guys. Really appreciate it. Apologies if I appear slow in responding. I'm giving up 20 years as a manager to start up this but still got my day job...for now! 

Have now changed the pre filters but without much noticeable difference. Will try the suggestion of flushing for an hour. 

And will invest in a booster pump regardless. 

Water pressure is just on 50psi. 

Not sure about the position of the gate valve. Pure freedom state it should be fully shut whearas some advice is to not fully shut it. May replace it regardless to eliminate as a potential problem. 

Will try and make some progress with it over the next few days as and when I get time! And will let you know how I solve it. 

Again, really appreciate the advice and guidance. 

Andy

 

Purefreedom drill a hole in the paddle to let water through. The hole is the size that will give the correct waste to pure ratio. Now I'm not sure how they decide what size hole to drill.Obviously if you wanted a 1 to 1 pure to waste ratio then hole would be smaller than if you wanted a 1 to 2 pure to waste ratio. I don't know what size hole they drill.

 

What I suggested was to buy a gate valve from a local plumbing supplier if you have too much waste water. This gate valve will not have a hole drilled through the paddle. You then need to ensure that the valve is always open but you adjust it accordingly to get the pure to waste ratio you want. When processing water you always need to have a portion of waste flushing away the impurities removed from the water.

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Andy Hill

Thanks Spruce, 

Yes. If I replace the gate valve, I'll go with that suggestion. 

Thank you 

Andy

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Part Timer
48 minutes ago, doug atkinson said:

We also have a 4040 booster pump under trials which has been specked out for us and the aim is 400 litres an hour.

 

Next on plan is a system doing 800 litres an hour.

I appreciate your answer will be as soon as possible but any timescale idea on the 800 litres an hour, as this would be a godsend for me on my travels.

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Pjj
2 minutes ago, Part Timer said:

I appreciate your answer will be as soon as possible but any timescale idea on the 800 litres an hour, as this would be a godsend for me on my travels.

Grippatank Do  an 800 ltr per hour booster pump I have one it’s an awesome piece of kit 

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