Water pressure conundrum

[Poppin]

Hoping someone can advise on water pressure issue. I have a 45psi whale water pump with accumulator. I have recently installed a triple filter after the pump, which is part of a wider system for the filtering of canal water. The triple filter has caused a pressure drop significant enough to cause a delay in the pump activating. I will attempt to adjust the pressure switch, bit since the cut out is fixed to 0.6 bar from the cut in, I am guessing my problems will continue. Can anyone advise on ideas?

[MtB]

Why does it matter if the pump doesn't activate immediately? I'd have thought the pressure switch would still turn it on when needed.

 

 

 

[Tony Brooks]

I think what you mean is that the resistance of the filters is so high, that when you turn the tap on the flow from the tap takes too long to drop the pressure in the accumulator and pre the filters, enough to make the pump cut in. I expect the cycling period with an open tap has increased as well. I very much doubt a higher pump cut out will help much because I think it is resistance to flow in the filters. The answer is to reduce the filters' resistances but as the OP talks about using canal water a larger pore size would be inadvisable, so all that leaves is one or more sets of filter piped in parallel.

[Tracy D'arth]

Is there a good reason for messing about filtering contaminated unpotable canal water?

[Alan de Enfield]

1 minute ago, Tracy D'arth said:

Is there a good reason for messing about filtering contaminated unpotable canal water?

 

 

It saves having to move - you just need to ensure that your toilet discharge pipe is downsteam of your abstraction 'pick-up' pipe.

[jonesthenuke]

If there is an accumulator there will normally be a delay in the pump starting after opening a tap. Increasing the flow resistance with filters will reduce the flow from the tap and consequently increase the time taken to get to the pump cut in pressure. If the flow is adequate it would not seem to be a problem, However 12V pumps that are typically used are not designed with filtration systems in mind so problems may well ensue, especially as the filters foul (and on canal water that would seem likely). If further filtration/water purification is added (as suggested in the OP) then greater problems may well arise with water flow rates if a single pump is used to push water through the whole system

[Poppin]

2 hours ago, Tony Brooks said:

I think what you mean is that the resistance of the filters is so high, that when you turn the tap on the flow from the tap takes too long to drop the pressure in the accumulator and pre the filters, enough to make the pump cut in. I expect the cycling period with an open tap has increased as well. I very much doubt a higher pump cut out will help much because I think it is resistance to flow in the filters. The answer is to reduce the filters' resistances but as the OP talks about using canal water a larger pore size would be inadvisable, so all that leaves is one or more sets of filter piped in parallel.

What do you mean by in parallel?

[Tony Brooks]

7 minutes ago, Poppin said:

What do you mean by in parallel?

 

Two or more sets of what you already have with their inlets fed by a common pipe and their outlets going to a common pipe. That way each may restrict the flow, but you get two or more times the flow by the parallel pathway. Hence, the pressure pre-filters drops faster so the pump cuts in sooner.

[Poppin]

34 minutes ago, Tony Brooks said:

 

Two or more sets of what you already have with their inlets fed by a common pipe and their outlets going to a common pipe. That way each may restrict the flow, but you get two or more times the flow by the parallel pathway. Hence, the pressure pre-filters drops faster so the pump cuts in sooner.

Ah I see, and I suppose the filters would last twice as long. Still, space concerns...

[Poppin]

4 hours ago, Tony Brooks said:

 

Two or more sets of what you already have with their inlets fed by a common pipe and their outlets going to a common pipe. That way each may restrict the flow, but you get two or more times the flow by the parallel pathway. Hence, the pressure pre-filters drops faster so the pump cuts in sooner.

Could I not install a second Ccumilator tank after the filters?

[mrsmelly]

My advice would be to simply fill your water tank with potable water from canal side taps or marinas rather than filter dirty water. Taps are the norm in most marinas or if a ccer I always found I passed one at the very least every other day.

[Machpoint005]

He lost my attention when he started mixing his pressure units (45psi, 0.6bar).

 

 

[Tony Brooks]

58 minutes ago, Poppin said:

Could I not install a second Ccumilator tank after the filters?

 

And as the pump will be on the other side of the filters, exactly how do you think that will help. It will make the delay until the pump cuts in even longer. You will get an initial spurt of water without the filter restriction, but it will soon drop to what you have now, then it will say the same until you turn the tap off, so the new accumulator recharges. Open the tap and the initial spurt, dropping to what you have now will just repeat.

 

I suppose that if you fitted an enormous second accumulator, it could supply a lot more water until the pressure dropped enough for the pump to cut in, but you have mentioned space considerations. So if you don't have room for a second set of filters, I can't see you have room for a giant accumulator.

[MtB]

14 hours ago, Machpoint005 said:

He lost my attention when he started mixing his pressure units (45psi, 0.6bar).

 

I think mrsmelly has it right. The best solution is to use clean tap water in the first place which does not need filtering, instead of canal water. 

[IanD]

21 hours ago, Alan de Enfield said:

 

It saves having to move - you just need to ensure that your toilet discharge pipe is downsteam of your abstraction 'pick-up' pipe.

Not allowed on the canals, obviously...

[Chewbacka]

16 minutes ago, IanD said:

Not allowed on the canals, obviously...

And if on a river you may well be downstream of the sewage works overflow so you need filters fine enough to remove e-coli and other disgusting things………..

[Alan de Enfield]

26 minutes ago, IanD said:

Not allowed on the canals, obviously...

 

There would appear to be quite a few boaters that are either unaware of that fact, or, more likely, just don't give a toss.

[DShK]

Nothing could convince me to touch "filtered" canal water.

 

I've seen enough people shilling those filters on facebook that I'm convinced it's some kind of MLM scheme.

Edited April 25 by DShK

[MtB]

1 hour ago, DShK said:

Nothing could convince me to touch "filtered" canal water.

 

I've seen enough people shilling those filters on facebook that I'm convinced it's some kind of MLM scheme.

 

 

Yes the whole idea strikes me as bizarre. 

 

 

 

 

[Tracy D'arth]

2 hours ago, DShK said:

Nothing could convince me to touch "filtered" canal water.

 

I've seen enough people shilling those filters on facebook that I'm convinced it's some kind of MLM scheme.

Its a silly and dangerous idea. Someone is going to get seriously sick and die doing this.  Darwin Awards candidates.

2 hours ago, DShK said:

 

 

Edited April 25 by Tracy D'arth

[Tony Brooks]

I can see some benefit if it is a totally separate system from the domestic water system. It could be used for toilet flushing, general cleaning and cloths washing provided it was got very hot first. It would save a little tank filling, but as for cooking, drinking and washing up, I think it is asking for health problems.

 

I would remind the OP that many years ago Thames Water was reported to have done checks in domestic properties, and they found that those with plumbed in water filters had worse quality water than those without because of nasties build p in the filter and the filters not being changed frequently enough. I also know what I found when I removed one of the ceramic filter drinking water taps when we bought our boat - lucky SWMBO did not see it.

 

If the OP is intent on using canal water for general use that he investigates ultraviolet sterilization, but dread to think about the electrical demands.

[TheBiscuits]

2 hours ago, DShK said:

Nothing could convince me to touch "filtered" canal water.

 

1 hour ago, MtB said:

Yes the whole idea strikes me as bizarre. 

 

You probably don't want to know how tap water gets processed and where from then ...

[Tracy D'arth]

5 minutes ago, TheBiscuits said:

 

 

You probably don't want to know how tap water gets processed and where from then ...

I know where potable water comes from and the processes involved in ensuring that it is to a safe standard.  It is much more involved than a few filters on a boat and it is constantly tested.

[TheBiscuits]

Just now, Tracy D'arth said:

I know where potable water comes from and the processes involved in ensuring that it is to a safe standard.  It is much more involved than a few filters on a boat and it is constantly tested.

 

Apart from the several billion litres of cryptosporidium infected water that United Utilities helpfully provided across the North West a few years ago.  Obviously.

 

[blackrose]

19 minutes ago, TheBiscuits said:

 

Apart from the several billion litres of cryptosporidium infected water that United Utilities helpfully provided across the North West a few years ago.  Obviously.

 

 

Yes apart from that and some other rare cases amongst the billions of gallons of clean drinking quality water delivered to consumers across the country every year.